include<bits/stdc++.h>

using namespace std;

int main() {
long a; cin >> a; if (a >= 1000) { cout << a / 1000 << a / 10 % 10 << a / 100 % 10 << a % 10; } else { cout << a / 10 % 10 << a / 100 % 10 << a % 10; } } //TECHNOBLADE NEVER DIES