2

#include <string>
#include <fstream>

using namespace std;

int main () {
    ifstream in;
    in.open("input.txt");

    string s, ans;
    ans = "";

    while (in >> s)
    {
        int i = 0;
        string word = "";
        while (i < s.length())
        {
            if (s[i] == ',' || s[i] == '.' || s[i] == '!' || s[i] == '?'
                && word.length() > ans.length())
            {
                ans = word;
            }
            else
            {
                word = word + s[i];
            }
            i++;
        }
        if (word.length() > ans.length())
        {
            ans = word;
        }
    }

    in.close();

    ofstream out;
    out.open("output.txt");

    out << ans << endl;
    out.close();
    return 0;
}