Envío 2089

Código

#include <iostream>
#include <bits/stdc++.h> 
using namespace std; 
int main() {
	
	string s;
	cin >> s;
	int count = 0;
	char begin = s[0];
	for(int i = 1;i < s.length(); i++){
		if(s[i] == begin && s[s.length() - i-1] == s[s.length()-1]){
			string sub = s.substr(0, s.length() - i);
			if(s.compare(i,sub.length(), sub) == 0){
				count = sub.length();
				break;
			}
		}
		
	}
	
	cout  << count;
	return 0;
}