import java.util.*;
class Main{
public static void main(String[] args){
Scanner sc=new Scanner(System.in);
int n=sc.nextInt();
int[] nums=new int[n];
for(int i=0;i<n;i++)nums[i]=sc.nextInt();
for(int i=1;i<n;i++){
if(nums[i-1]<nums[i])nums[i]--;
else if(nums[i-1]>nums[i]){System.out.println("No");
return;}
}
System.out.println("Yes");
}} import java.util.*; util.* java class Main{
public static void main(String[] args){
Scanner sc=new Scanner(System.in);
int n=sc.nextInt();
int[] nums=new int[n];
for(int i=0;i<n;i++)nums[i]=sc.nextInt();
for(int i=1;i<n;i++){
if(nums[i-1]<nums[i])nums[i]--;
else if(nums[i-1]>nums[i]){System.out.println("No");
return;}
}
System.out.println("Yes");
}} Main public static void main(String[] args){
Scanner sc=new Scanner(System.in);
int n=sc.nextInt();
int[] nums=new int[n];
for(int i=0;i<n;i++)nums[i]=sc.nextInt();
for(int i=1;i<n;i++){
if(nums[i-1]<nums[i])nums[i]--;
else if(nums[i-1]>nums[i]){System.out.println("No");
return;}
}
System.out.println("Yes");
} main {
Scanner sc=new Scanner(System.in);
int n=sc.nextInt();
int[] nums=new int[n];
for(int i=0;i<n;i++)nums[i]=sc.nextInt();
for(int i=1;i<n;i++){
if(nums[i-1]<nums[i])nums[i]--;
else if(nums[i-1]>nums[i]){System.out.println("No");
return;}
}
System.out.println("Yes");
} Scanner sc=new Scanner(System.in); sc new Scanner(System.in) int n=sc.nextInt(); n sc.nextInt() sc.nextInt sc int[] nums=new int[n]; nums new int[n] n for(int i=0;i<n;i++)nums[i]=sc.nextInt(); int i=0; int i=0; i 0 i<n i n i++ i++ i nums[i]=sc.nextInt(); nums[i]=sc.nextInt() nums[i] nums i sc.nextInt() sc.nextInt sc for(int i=1;i<n;i++){
if(nums[i-1]<nums[i])nums[i]--;
else if(nums[i-1]>nums[i]){System.out.println("No");
return;}
} int i=1; int i=1; i 1 i<n i n i++ i++ i {
if(nums[i-1]<nums[i])nums[i]--;
else if(nums[i-1]>nums[i]){System.out.println("No");
return;}
} {
if(nums[i-1]<nums[i])nums[i]--;
else if(nums[i-1]>nums[i]){System.out.println("No");
return;}
} if(nums[i-1]<nums[i])nums[i]--;
else if(nums[i-1]>nums[i]){System.out.println("No");
return;} nums[i-1]<nums[i] nums[i-1] nums i-1 i 1 nums[i] nums i nums[i]-- nums[i] nums i if(nums[i-1]>nums[i]){System.out.println("No");
return;} nums[i-1]>nums[i] nums[i-1] nums i-1 i 1 nums[i] nums i {System.out.println("No");
return;} System.out.println("No") System.out.println System.out System System.out "No" return; System.out.println("Yes") System.out.println System.out System System.out "Yes" String[] args args
import java.util.*;
class Main{
public static void main(String[] args){
Scanner sc=new Scanner(System.in);
int n=sc.nextInt();
int[] nums=new int[n];
for(int i=0;i<n;i++)nums[i]=sc.nextInt();
for(int i=1;i<n;i++){
if(nums[i-1]<nums[i])nums[i]--;
else if(nums[i-1]>nums[i]){System.out.println("No");
return;}
}
System.out.println("Yes");
}}