#include<bits/stdc++.h> using namespace std; int main() { int a; cin >> a; int b = a / 1000; int c = (a / 100) % 10; int d = (a / 10) % 10; int e = a % 10; int f = c * 1000 + b * 100 + e * 10 + d * 1; cout << f; return 0; }