#include <iostream>
#include <string>
using namespace std;

#define endl "\n"

int main(void) {
    string str, smax, tmax;
    getline(cin, str);
    for (char c : str) {
        if (c != 0x20)
            tmax.push_back(c);
        else {
            if (tmax.size() > smax.size())
                smax = tmax;
            tmax.clear();
        }
    }
    if (tmax.size() > smax.size())
        smax = tmax;
    cout << smax << endl;
    return 0;
}