#include<bits/stdc++.h> using namespace std; int main(){ /** int a1,a2,n; cin>>a1>>a2>>n; cout<<a1+(n-1)*(a2-a1); int a,b,c; cin>>a>>b>>c; cout<<a<<b<<c; **/ int a,b,c,d,m; cin>>m; a=m/1000; m=m%1000; b=m/100; m=m%100; c=m/10; m=m%10; d=m/1; cout<<b<<a<<d<<c; return 0; }