ICPC -Hangman v2

#include <iostream>
#include <cstring>
#include <list>
using namespace std;

int main ()
{
    int round;

    while (cin >> round) {

        if (round == -1){
            return 0;
        }

        char solution [2000], guess [2000];

        cin >> solution;
        cin >> guess;

        int length = strlen (solution);
        list <char> l (&solution [0], &solution [length]);

        int stroke = 0;
        length = strlen(guess);

        for (int i = 0; i < length; i++) {
            if (!l.empty()){
                int tempSize = l.size ();
                l.remove (guess [i]);
                if (tempSize == l.size ()){
                    stroke++;
                }
            }
            else{
                break;
            }
        }
        cout << "Round " << round << endl;

        if (l.empty () && stroke < 7) {
            cout << "You win." << endl;
        }
        else if (!l.empty () && stroke < 7) {
            cout << "You chickened out." << endl;
        }
        else {
            cout << "You lose." << endl;
        }
    }

    return 0;
}