#include <bits/stdc++.h>

using namespace std;

int main()
{
    string s;

    getline(cin, s);
    s.pop_back();
    stringstream ssin(s);

    string str;
    int cnt = 0;
    string fin;
    while(ssin >> str)
    {
        int c = str.size();
        if(c > cnt) {cnt = c; fin = str;}
    }
    cout << fin << endl;

    return 0;
}