#include <bits/stdc++.h>
using namespace std;
int main(){
	int n;
	cin>>n;
	cout<<n/1000+n/100%10*10+n/10%10*100+n%10*1000;
}

/**************************************************************
	Problem: 1029
	User: zhouhongyi
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/