# include<iostream> # include<cstdio> # include<iomanip> using namespace std; int main(){ int a,ge,shi,bai,qian; cin>>a; ge=a%10; shi=a%100/10; bai=a%1000/100; qian=a/1000; cout<<bai*1000+qian*100+ge*10+shi; return 0; }