#include<bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int,int>;
const int N = 10;
int t,n,m,k,l,r,op,x,y;
int f[N];
string str;
void solve(){
    while(cin>>str){
        memset(f,0,sizeof(f));
        for(char&ch:str)f[ch-'0']++;
        cout<<(max_element(f,f+N)-f)<<"\n";
    }
}
int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);  
    solve();
    return 0;
}