import java.util.*;
public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		// 整数の入力
      	int i,j;
        int c[][] = new int[3][3];
      	int check = 0;
        int a[] = new int[3];
        int b[] = new int[3];      
        for(i = 0;i<3;i++){
         for(j=0;j<3;j++){
           c[i][j] = sc.nextInt();
         }
        }
      
        if(c[0][0] == 0){
          a[0] = 0;
          b[0] = c[0][0];
          a[1] = c[1][0] - b[0];
          a[2] = c[2][0] - b[0];
			for(j = 0;j< 3;j++){
                if(c[0][j] - a[0] != c[1][j] - a[1] || c[1][j] - a[1] != c[2][j] - a[2]){
                       System.out.println("No"); 
               		System.exit(0);
                  }
                }
                 System.out.println("Yes"); 
                 System.exit(0);
              
          }else{
		  for(i = 0;i <= c[0][0]; i++){
            a[0] = i;
            b[0] = c[0][0] - a[0];
            a[1] = c[1][0] - b[0];
            a[2] = c[2][0] - b[0];
            b[1] = c[1][1] - a[1];
            b[2] = c[2][2] - a[2];
             if(a[1] >=0 && a[2] >=0 && b[1] >= 0 && b[2] >= 0){
				for(j = 0;j< 3;j++){
                  if(c[0][j] - a[0] != c[1][j] - a[1] || c[1][j] - a[1] != c[2][j] - a[2]){
                         System.out.println("No"); 
               			 System.exit(0);
                  }
                }
                 System.out.println("Yes"); 
                 System.exit(0);
              }


            
          }
        }
        System.out.println("No"); 
    }
} import java.util.*; util.* java public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		// 整数の入力
      	int i,j;
        int c[][] = new int[3][3];
      	int check = 0;
        int a[] = new int[3];
        int b[] = new int[3];      
        for(i = 0;i<3;i++){
         for(j=0;j<3;j++){
           c[i][j] = sc.nextInt();
         }
        }
      
        if(c[0][0] == 0){
          a[0] = 0;
          b[0] = c[0][0];
          a[1] = c[1][0] - b[0];
          a[2] = c[2][0] - b[0];
			for(j = 0;j< 3;j++){
                if(c[0][j] - a[0] != c[1][j] - a[1] || c[1][j] - a[1] != c[2][j] - a[2]){
                       System.out.println("No"); 
               		System.exit(0);
                  }
                }
                 System.out.println("Yes"); 
                 System.exit(0);
              
          }else{
		  for(i = 0;i <= c[0][0]; i++){
            a[0] = i;
            b[0] = c[0][0] - a[0];
            a[1] = c[1][0] - b[0];
            a[2] = c[2][0] - b[0];
            b[1] = c[1][1] - a[1];
            b[2] = c[2][2] - a[2];
             if(a[1] >=0 && a[2] >=0 && b[1] >= 0 && b[2] >= 0){
				for(j = 0;j< 3;j++){
                  if(c[0][j] - a[0] != c[1][j] - a[1] || c[1][j] - a[1] != c[2][j] - a[2]){
                         System.out.println("No"); 
               			 System.exit(0);
                  }
                }
                 System.out.println("Yes"); 
                 System.exit(0);
              }


            
          }
        }
        System.out.println("No"); 
    }
} Main public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		// 整数の入力
      	int i,j;
        int c[][] = new int[3][3];
      	int check = 0;
        int a[] = new int[3];
        int b[] = new int[3];      
        for(i = 0;i<3;i++){
         for(j=0;j<3;j++){
           c[i][j] = sc.nextInt();
         }
        }
      
        if(c[0][0] == 0){
          a[0] = 0;
          b[0] = c[0][0];
          a[1] = c[1][0] - b[0];
          a[2] = c[2][0] - b[0];
			for(j = 0;j< 3;j++){
                if(c[0][j] - a[0] != c[1][j] - a[1] || c[1][j] - a[1] != c[2][j] - a[2]){
                       System.out.println("No"); 
               		System.exit(0);
                  }
                }
                 System.out.println("Yes"); 
                 System.exit(0);
              
          }else{
		  for(i = 0;i <= c[0][0]; i++){
            a[0] = i;
            b[0] = c[0][0] - a[0];
            a[1] = c[1][0] - b[0];
            a[2] = c[2][0] - b[0];
            b[1] = c[1][1] - a[1];
            b[2] = c[2][2] - a[2];
             if(a[1] >=0 && a[2] >=0 && b[1] >= 0 && b[2] >= 0){
				for(j = 0;j< 3;j++){
                  if(c[0][j] - a[0] != c[1][j] - a[1] || c[1][j] - a[1] != c[2][j] - a[2]){
                         System.out.println("No"); 
               			 System.exit(0);
                  }
                }
                 System.out.println("Yes"); 
                 System.exit(0);
              }


            
          }
        }
        System.out.println("No"); 
    } main {
		Scanner sc = new Scanner(System.in);
		// 整数の入力
      	int i,j;
        int c[][] = new int[3][3];
      	int check = 0;
        int a[] = new int[3];
        int b[] = new int[3];      
        for(i = 0;i<3;i++){
         for(j=0;j<3;j++){
           c[i][j] = sc.nextInt();
         }
        }
      
        if(c[0][0] == 0){
          a[0] = 0;
          b[0] = c[0][0];
          a[1] = c[1][0] - b[0];
          a[2] = c[2][0] - b[0];
			for(j = 0;j< 3;j++){
                if(c[0][j] - a[0] != c[1][j] - a[1] || c[1][j] - a[1] != c[2][j] - a[2]){
                       System.out.println("No"); 
               		System.exit(0);
                  }
                }
                 System.out.println("Yes"); 
                 System.exit(0);
              
          }else{
		  for(i = 0;i <= c[0][0]; i++){
            a[0] = i;
            b[0] = c[0][0] - a[0];
            a[1] = c[1][0] - b[0];
            a[2] = c[2][0] - b[0];
            b[1] = c[1][1] - a[1];
            b[2] = c[2][2] - a[2];
             if(a[1] >=0 && a[2] >=0 && b[1] >= 0 && b[2] >= 0){
				for(j = 0;j< 3;j++){
                  if(c[0][j] - a[0] != c[1][j] - a[1] || c[1][j] - a[1] != c[2][j] - a[2]){
                         System.out.println("No"); 
               			 System.exit(0);
                  }
                }
                 System.out.println("Yes"); 
                 System.exit(0);
              }


            
          }
        }
        System.out.println("No"); 
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int i i j; j int c[][] = new int[3][3]; c new int[3][3] 3 3 int check = 0; check 0 int a[] = new int[3]; a new int[3] 3 int b[] = new int[3]; b new int[3] 3 for(i = 0;i<3;i++){
         for(j=0;j<3;j++){
           c[i][j] = sc.nextInt();
         }
        } i = 0; i = 0 i 0 i<3 i 3 i++ i++ i {
         for(j=0;j<3;j++){
           c[i][j] = sc.nextInt();
         }
        } {
         for(j=0;j<3;j++){
           c[i][j] = sc.nextInt();
         }
        } for(j=0;j<3;j++){
           c[i][j] = sc.nextInt();
         } j=0; j=0 j 0 j<3 j 3 j++ j++ j {
           c[i][j] = sc.nextInt();
         } {
           c[i][j] = sc.nextInt();
         } c[i][j] = sc.nextInt() c[i][j] c[i] c i j sc.nextInt() sc.nextInt sc if(c[0][0] == 0){
          a[0] = 0;
          b[0] = c[0][0];
          a[1] = c[1][0] - b[0];
          a[2] = c[2][0] - b[0];
			for(j = 0;j< 3;j++){
                if(c[0][j] - a[0] != c[1][j] - a[1] || c[1][j] - a[1] != c[2][j] - a[2]){
                       System.out.println("No"); 
               		System.exit(0);
                  }
                }
                 System.out.println("Yes"); 
                 System.exit(0);
              
          }else{
		  for(i = 0;i <= c[0][0]; i++){
            a[0] = i;
            b[0] = c[0][0] - a[0];
            a[1] = c[1][0] - b[0];
            a[2] = c[2][0] - b[0];
            b[1] = c[1][1] - a[1];
            b[2] = c[2][2] - a[2];
             if(a[1] >=0 && a[2] >=0 && b[1] >= 0 && b[2] >= 0){
				for(j = 0;j< 3;j++){
                  if(c[0][j] - a[0] != c[1][j] - a[1] || c[1][j] - a[1] != c[2][j] - a[2]){
                         System.out.println("No"); 
               			 System.exit(0);
                  }
                }
                 System.out.println("Yes"); 
                 System.exit(0);
              }


            
          }
        } c[0][0] == 0 c[0][0] c[0] c 0 0 0 {
          a[0] = 0;
          b[0] = c[0][0];
          a[1] = c[1][0] - b[0];
          a[2] = c[2][0] - b[0];
			for(j = 0;j< 3;j++){
                if(c[0][j] - a[0] != c[1][j] - a[1] || c[1][j] - a[1] != c[2][j] - a[2]){
                       System.out.println("No"); 
               		System.exit(0);
                  }
                }
                 System.out.println("Yes"); 
                 System.exit(0);
              
          } a[0] = 0 a[0] a 0 0 b[0] = c[0][0] b[0] b 0 c[0][0] c[0] c 0 0 a[1] = c[1][0] - b[0] a[1] a 1 c[1][0] - b[0] c[1][0] c[1] c 1 0 b[0] b 0 a[2] = c[2][0] - b[0] a[2] a 2 c[2][0] - b[0] c[2][0] c[2] c 2 0 b[0] b 0 for(j = 0;j< 3;j++){
                if(c[0][j] - a[0] != c[1][j] - a[1] || c[1][j] - a[1] != c[2][j] - a[2]){
                       System.out.println("No"); 
               		System.exit(0);
                  }
                } j = 0; j = 0 j 0 j< 3 j 3 j++ j++ j {
                if(c[0][j] - a[0] != c[1][j] - a[1] || c[1][j] - a[1] != c[2][j] - a[2]){
                       System.out.println("No"); 
               		System.exit(0);
                  }
                } {
                if(c[0][j] - a[0] != c[1][j] - a[1] || c[1][j] - a[1] != c[2][j] - a[2]){
                       System.out.println("No"); 
               		System.exit(0);
                  }
                } if(c[0][j] - a[0] != c[1][j] - a[1] || c[1][j] - a[1] != c[2][j] - a[2]){
                       System.out.println("No"); 
               		System.exit(0);
                  } c[0][j] - a[0] != c[1][j] - a[1] || c[1][j] - a[1] != c[2][j] - a[2] c[0][j] - a[0] != c[1][j] - a[1] c[0][j] - a[0] c[0][j] c[0] c 0 j a[0] a 0 c[1][j] - a[1] c[1][j] c[1] c 1 j a[1] a 1 c[1][j] - a[1] != c[2][j] - a[2] c[1][j] - a[1] c[1][j] c[1] c 1 j a[1] a 1 c[2][j] - a[2] c[2][j] c[2] c 2 j a[2] a 2 {
                       System.out.println("No"); 
               		System.exit(0);
                  } System.out.println("No") System.out.println System.out System System.out "No" System.exit(0) System.exit System 0 System.out.println("Yes") System.out.println System.out System System.out "Yes" System.exit(0) System.exit System 0 {
		  for(i = 0;i <= c[0][0]; i++){
            a[0] = i;
            b[0] = c[0][0] - a[0];
            a[1] = c[1][0] - b[0];
            a[2] = c[2][0] - b[0];
            b[1] = c[1][1] - a[1];
            b[2] = c[2][2] - a[2];
             if(a[1] >=0 && a[2] >=0 && b[1] >= 0 && b[2] >= 0){
				for(j = 0;j< 3;j++){
                  if(c[0][j] - a[0] != c[1][j] - a[1] || c[1][j] - a[1] != c[2][j] - a[2]){
                         System.out.println("No"); 
               			 System.exit(0);
                  }
                }
                 System.out.println("Yes"); 
                 System.exit(0);
              }


            
          }
        } for(i = 0;i <= c[0][0]; i++){
            a[0] = i;
            b[0] = c[0][0] - a[0];
            a[1] = c[1][0] - b[0];
            a[2] = c[2][0] - b[0];
            b[1] = c[1][1] - a[1];
            b[2] = c[2][2] - a[2];
             if(a[1] >=0 && a[2] >=0 && b[1] >= 0 && b[2] >= 0){
				for(j = 0;j< 3;j++){
                  if(c[0][j] - a[0] != c[1][j] - a[1] || c[1][j] - a[1] != c[2][j] - a[2]){
                         System.out.println("No"); 
               			 System.exit(0);
                  }
                }
                 System.out.println("Yes"); 
                 System.exit(0);
              }


            
          } i = 0; i = 0 i 0 i <= c[0][0] i c[0][0] c[0] c 0 0 i++ i++ i {
            a[0] = i;
            b[0] = c[0][0] - a[0];
            a[1] = c[1][0] - b[0];
            a[2] = c[2][0] - b[0];
            b[1] = c[1][1] - a[1];
            b[2] = c[2][2] - a[2];
             if(a[1] >=0 && a[2] >=0 && b[1] >= 0 && b[2] >= 0){
				for(j = 0;j< 3;j++){
                  if(c[0][j] - a[0] != c[1][j] - a[1] || c[1][j] - a[1] != c[2][j] - a[2]){
                         System.out.println("No"); 
               			 System.exit(0);
                  }
                }
                 System.out.println("Yes"); 
                 System.exit(0);
              }


            
          } {
            a[0] = i;
            b[0] = c[0][0] - a[0];
            a[1] = c[1][0] - b[0];
            a[2] = c[2][0] - b[0];
            b[1] = c[1][1] - a[1];
            b[2] = c[2][2] - a[2];
             if(a[1] >=0 && a[2] >=0 && b[1] >= 0 && b[2] >= 0){
				for(j = 0;j< 3;j++){
                  if(c[0][j] - a[0] != c[1][j] - a[1] || c[1][j] - a[1] != c[2][j] - a[2]){
                         System.out.println("No"); 
               			 System.exit(0);
                  }
                }
                 System.out.println("Yes"); 
                 System.exit(0);
              }


            
          } a[0] = i a[0] a 0 i b[0] = c[0][0] - a[0] b[0] b 0 c[0][0] - a[0] c[0][0] c[0] c 0 0 a[0] a 0 a[1] = c[1][0] - b[0] a[1] a 1 c[1][0] - b[0] c[1][0] c[1] c 1 0 b[0] b 0 a[2] = c[2][0] - b[0] a[2] a 2 c[2][0] - b[0] c[2][0] c[2] c 2 0 b[0] b 0 b[1] = c[1][1] - a[1] b[1] b 1 c[1][1] - a[1] c[1][1] c[1] c 1 1 a[1] a 1 b[2] = c[2][2] - a[2] b[2] b 2 c[2][2] - a[2] c[2][2] c[2] c 2 2 a[2] a 2 if(a[1] >=0 && a[2] >=0 && b[1] >= 0 && b[2] >= 0){
				for(j = 0;j< 3;j++){
                  if(c[0][j] - a[0] != c[1][j] - a[1] || c[1][j] - a[1] != c[2][j] - a[2]){
                         System.out.println("No"); 
               			 System.exit(0);
                  }
                }
                 System.out.println("Yes"); 
                 System.exit(0);
              } a[1] >=0 && a[2] >=0 && b[1] >= 0 && b[2] >= 0 b[1] >= 0 a[1] >=0 && a[2] >=0 && b[1] >= 0 && b[2] >= 0 a[1] >=0 a[1] a 1 0 a[2] >=0 a[2] a 2 0 b[1] >= 0 b[1] b 1 0 b[2] >= 0 b[2] b 2 0 {
				for(j = 0;j< 3;j++){
                  if(c[0][j] - a[0] != c[1][j] - a[1] || c[1][j] - a[1] != c[2][j] - a[2]){
                         System.out.println("No"); 
               			 System.exit(0);
                  }
                }
                 System.out.println("Yes"); 
                 System.exit(0);
              } for(j = 0;j< 3;j++){
                  if(c[0][j] - a[0] != c[1][j] - a[1] || c[1][j] - a[1] != c[2][j] - a[2]){
                         System.out.println("No"); 
               			 System.exit(0);
                  }
                } j = 0; j = 0 j 0 j< 3 j 3 j++ j++ j {
                  if(c[0][j] - a[0] != c[1][j] - a[1] || c[1][j] - a[1] != c[2][j] - a[2]){
                         System.out.println("No"); 
               			 System.exit(0);
                  }
                } {
                  if(c[0][j] - a[0] != c[1][j] - a[1] || c[1][j] - a[1] != c[2][j] - a[2]){
                         System.out.println("No"); 
               			 System.exit(0);
                  }
                } if(c[0][j] - a[0] != c[1][j] - a[1] || c[1][j] - a[1] != c[2][j] - a[2]){
                         System.out.println("No"); 
               			 System.exit(0);
                  } c[0][j] - a[0] != c[1][j] - a[1] || c[1][j] - a[1] != c[2][j] - a[2] c[0][j] - a[0] != c[1][j] - a[1] c[0][j] - a[0] c[0][j] c[0] c 0 j a[0] a 0 c[1][j] - a[1] c[1][j] c[1] c 1 j a[1] a 1 c[1][j] - a[1] != c[2][j] - a[2] c[1][j] - a[1] c[1][j] c[1] c 1 j a[1] a 1 c[2][j] - a[2] c[2][j] c[2] c 2 j a[2] a 2 {
                         System.out.println("No"); 
               			 System.exit(0);
                  } System.out.println("No") System.out.println System.out System System.out "No" System.exit(0) System.exit System 0 System.out.println("Yes") System.out.println System.out System System.out "Yes" System.exit(0) System.exit System 0 System.out.println("No") System.out.println System.out System System.out "No" String[] args args public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		// 整数の入力
      	int i,j;
        int c[][] = new int[3][3];
      	int check = 0;
        int a[] = new int[3];
        int b[] = new int[3];      
        for(i = 0;i<3;i++){
         for(j=0;j<3;j++){
           c[i][j] = sc.nextInt();
         }
        }
      
        if(c[0][0] == 0){
          a[0] = 0;
          b[0] = c[0][0];
          a[1] = c[1][0] - b[0];
          a[2] = c[2][0] - b[0];
			for(j = 0;j< 3;j++){
                if(c[0][j] - a[0] != c[1][j] - a[1] || c[1][j] - a[1] != c[2][j] - a[2]){
                       System.out.println("No"); 
               		System.exit(0);
                  }
                }
                 System.out.println("Yes"); 
                 System.exit(0);
              
          }else{
		  for(i = 0;i <= c[0][0]; i++){
            a[0] = i;
            b[0] = c[0][0] - a[0];
            a[1] = c[1][0] - b[0];
            a[2] = c[2][0] - b[0];
            b[1] = c[1][1] - a[1];
            b[2] = c[2][2] - a[2];
             if(a[1] >=0 && a[2] >=0 && b[1] >= 0 && b[2] >= 0){
				for(j = 0;j< 3;j++){
                  if(c[0][j] - a[0] != c[1][j] - a[1] || c[1][j] - a[1] != c[2][j] - a[2]){
                         System.out.println("No"); 
               			 System.exit(0);
                  }
                }
                 System.out.println("Yes"); 
                 System.exit(0);
              }


            
          }
        }
        System.out.println("No"); 
    }
} public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		// 整数の入力
      	int i,j;
        int c[][] = new int[3][3];
      	int check = 0;
        int a[] = new int[3];
        int b[] = new int[3];      
        for(i = 0;i<3;i++){
         for(j=0;j<3;j++){
           c[i][j] = sc.nextInt();
         }
        }
      
        if(c[0][0] == 0){
          a[0] = 0;
          b[0] = c[0][0];
          a[1] = c[1][0] - b[0];
          a[2] = c[2][0] - b[0];
			for(j = 0;j< 3;j++){
                if(c[0][j] - a[0] != c[1][j] - a[1] || c[1][j] - a[1] != c[2][j] - a[2]){
                       System.out.println("No"); 
               		System.exit(0);
                  }
                }
                 System.out.println("Yes"); 
                 System.exit(0);
              
          }else{
		  for(i = 0;i <= c[0][0]; i++){
            a[0] = i;
            b[0] = c[0][0] - a[0];
            a[1] = c[1][0] - b[0];
            a[2] = c[2][0] - b[0];
            b[1] = c[1][1] - a[1];
            b[2] = c[2][2] - a[2];
             if(a[1] >=0 && a[2] >=0 && b[1] >= 0 && b[2] >= 0){
				for(j = 0;j< 3;j++){
                  if(c[0][j] - a[0] != c[1][j] - a[1] || c[1][j] - a[1] != c[2][j] - a[2]){
                         System.out.println("No"); 
               			 System.exit(0);
                  }
                }
                 System.out.println("Yes"); 
                 System.exit(0);
              }


            
          }
        }
        System.out.println("No"); 
    }
} Main
import java.util.*;
public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		// 整数の入力
      	int i,j;
        int c[][] = new int[3][3];
      	int check = 0;
        int a[] = new int[3];
        int b[] = new int[3];      
        for(i = 0;i<3;i++){
         for(j=0;j<3;j++){
           c[i][j] = sc.nextInt();
         }
        }
      
        if(c[0][0] == 0){
          a[0] = 0;
          b[0] = c[0][0];
          a[1] = c[1][0] - b[0];
          a[2] = c[2][0] - b[0];
			for(j = 0;j< 3;j++){
                if(c[0][j] - a[0] != c[1][j] - a[1] || c[1][j] - a[1] != c[2][j] - a[2]){
                       System.out.println("No"); 
               		System.exit(0);
                  }
                }
                 System.out.println("Yes"); 
                 System.exit(0);
              
          }else{
		  for(i = 0;i <= c[0][0]; i++){
            a[0] = i;
            b[0] = c[0][0] - a[0];
            a[1] = c[1][0] - b[0];
            a[2] = c[2][0] - b[0];
            b[1] = c[1][1] - a[1];
            b[2] = c[2][2] - a[2];
             if(a[1] >=0 && a[2] >=0 && b[1] >= 0 && b[2] >= 0){
				for(j = 0;j< 3;j++){
                  if(c[0][j] - a[0] != c[1][j] - a[1] || c[1][j] - a[1] != c[2][j] - a[2]){
                         System.out.println("No"); 
               			 System.exit(0);
                  }
                }
                 System.out.println("Yes"); 
                 System.exit(0);
              }


            
          }
        }
        System.out.println("No"); 
    }
}