Envío 2029

Código

#include <bits/stdc++.h>

using namespace std;

int main() {
    string s;
    cin >> s;
    int left = 0;
    int right = s.size();
    int c = 0;
    string testingString = "";
    for (int i = 0; i < right - 1; i++) {
        testingString += s[i];
        string substring = s.substr(right - testingString.size());
        if (s[i] == s[right - 1] and substring == testingString){
            int size = testingString.size();
            c = max(c, size);
        }
    }
    cout << c << endl;

}