#include <iostream> using namespace std; int main(){ int num; cin >> num; int A = num % 10; int B = (num / 10) % 10; int C = (num / 100) % 10; int D = num / 1000; int ne = A * 1000 + D * 100 + B * 10 + C; cout << ne<< endl; return 0; }