#include <iostream>
using namespace std;
int main() {
// Introduc variabilele a, b, c şi x;
int a, b, c, x;
// Citesc a, b, c, x;
cin >> a >> b >> c >> x;
if (c == x % 10) {// daca restul lui x e egal cu c
// Introduc variabila “cnt” sa numar cifrele;
int cnt = 0;
// parcurg x;
while (x > 0) {
++cnt;
b = x;
x /= 10;
}
cout << b;
//cout << cnt;// cnt = "a"
}
return 0;
}
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