#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<ctype.h>

#define MAX_SIZE 1000
int is_valid_integer(const char*s)
{
    if(!s||*s=='\0') return 0;
    int i=0;
    if(s[i]=='-')i++;
    if(s[i]=='\0')return 0;
    
    while(s[i]!='\0')
    {
        if(!isdigit((unsigned char)s[i]))
        {
            return 0;
        }
        i++;
    }
    return 1;

}
void solve()
{
    int lis[MAX_SIZE];
    int count=0;
    char token[20];
    
    while(scanf("%s",token)==1)
    {
      if(strcmp(token,"1")==0)
      {
          break;
      }
    }
    
    if(!is_valid_integer(token))
    {
        printf("Invalid input\n");
        return;
    }
    
    if(count<MAX_SIZE)
    {
        lis[count]=atoi(token);
        count++;
    }
}
if(count == 0)
{
    printf("YEs\n");
    return;
}

int start=0;
int end= count - 1;

while(start<end)
{
    if(list[start]!=list[end])
    {
        printf("No\n");
        return;
    }
    start++;
    end--;
}

printf("Yes\n");
}
int main()
{
    solve();
    return 0;
}