import java.util.Scanner;
public class Main {
	
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        int A = sc.nextInt();
        int B = sc.nextInt();
        int C = sc.nextInt();
        
        if( A-B > C ){
        	System.out.println( 0 );
        }
        else{
        	System.out.println( C - (A-B) );
        }
        
        sc.close();
    }
} import java.util.Scanner; Scanner java.util public class Main {
	
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        int A = sc.nextInt();
        int B = sc.nextInt();
        int C = sc.nextInt();
        
        if( A-B > C ){
        	System.out.println( 0 );
        }
        else{
        	System.out.println( C - (A-B) );
        }
        
        sc.close();
    }
} Main public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        int A = sc.nextInt();
        int B = sc.nextInt();
        int C = sc.nextInt();
        
        if( A-B > C ){
        	System.out.println( 0 );
        }
        else{
        	System.out.println( C - (A-B) );
        }
        
        sc.close();
    } main {
        Scanner sc = new Scanner(System.in);
        int A = sc.nextInt();
        int B = sc.nextInt();
        int C = sc.nextInt();
        
        if( A-B > C ){
        	System.out.println( 0 );
        }
        else{
        	System.out.println( C - (A-B) );
        }
        
        sc.close();
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int A = sc.nextInt(); A sc.nextInt() sc.nextInt sc int B = sc.nextInt(); B sc.nextInt() sc.nextInt sc int C = sc.nextInt(); C sc.nextInt() sc.nextInt sc if( A-B > C ){
        	System.out.println( 0 );
        }
        else{
        	System.out.println( C - (A-B) );
        } A-B > C A-B A B C {
        	System.out.println( 0 );
        } System.out.println( 0 ) System.out.println System.out System System.out 0 {
        	System.out.println( C - (A-B) );
        } System.out.println( C - (A-B) ) System.out.println System.out System System.out C - (A-B) C (A-B) A B sc.close() sc.close sc String[] args args public class Main {
	
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        int A = sc.nextInt();
        int B = sc.nextInt();
        int C = sc.nextInt();
        
        if( A-B > C ){
        	System.out.println( 0 );
        }
        else{
        	System.out.println( C - (A-B) );
        }
        
        sc.close();
    }
} public class Main {
	
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        int A = sc.nextInt();
        int B = sc.nextInt();
        int C = sc.nextInt();
        
        if( A-B > C ){
        	System.out.println( 0 );
        }
        else{
        	System.out.println( C - (A-B) );
        }
        
        sc.close();
    }
} Main
import java.util.Scanner;
public class Main {
	
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        int A = sc.nextInt();
        int B = sc.nextInt();
        int C = sc.nextInt();
        
        if( A-B > C ){
        	System.out.println( 0 );
        }
        else{
        	System.out.println( C - (A-B) );
        }
        
        sc.close();
    }
}