#include<bits/stdc++.h> 
using namespace std;
int main(){
	int x,s,a,b,c,d;
	cin>>x;
	a=x%10;
	b=x/10%10;
	c=x/100%10;
	d=x/1000;
	s=c*1000+d*100+b+a*10;
	cout<<s;
	
	
}
/**************************************************************
	Problem: 1619
	User: lvrenxiang
	Language: C++
	Result: Accepted
	Time:9 ms
	Memory:2072 kb
****************************************************************/