#include<stdio.h>
int main(){
    int a;
    while(scanf("%d",&a)!=EOF){
            int t,p,i;
            for(i=a+1;i>a;i++){
             p=i; int b=i;
            t=0;
            while(b!=0){
                t=t*10+b%10;
                b=b/10;
            }
            if(t==p){
                printf("%d\n",p); break;
            }

            }
    }
    return 0;
}

/**************************************************************
	Problem: 2094
	User: admin
	Language: C
	Result: Accepted
	Time:35 ms
	Memory:1144 kb
****************************************************************/