#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
using namespace std;
string ss;
int len,mid_1,mid_2;
void out(int x,int y,int pd,int num){
    if(pd==1){
        cout<<1;
        for(int i=1;i<len;i++) cout<<0;
        cout<<1; return;
    }
    int js=0;
    for(int i=0;i<=mid_2;i++){
        if(i<mid_1){
            cout<<ss[i]; ++js;
        }
        if(i==mid_1) cout<<num;
        if(i>mid_1&&i<mid_2) cout<<ss[i];
        if(i==mid_2) cout<<num;
    }
    int i=1;
    while(js>0){
        cout<<ss[mid_1-i];
        js--; i++;
    }
    
}
void deal(){
    while(ss[mid_1]==ss[mid_2]){
        mid_1--; mid_2++;
        if(mid_1<0||mid_2>=len){
            out(5,2,1,0); return;
        }
    }
    if(ss[mid_1]>ss[mid_2]){
        out(mid_1,mid_2,0,(ss[mid_1]^48)); return;
    }
    if(ss[mid_1]==ss[mid_2]){
        out(mid_1,mid_2,0,(ss[mid_1]^48)+1); return;
    }
    if(ss[mid_1]<ss[mid_2]){
        out(mid_1,mid_2,0,(ss[mid_2]^48)); return;
    }
    
}
int main(){
    cin>>ss;
    len=ss.size();
    if(len%2==1){
        mid_1=mid_2=len/2;
    }else{
        mid_2=len/2;
        mid_1=mid_2-1;
    }
    deal();
    return 0;
}