#include<bits/stdc++.h>
using namespace std;
class rollback
{
public:
int n,m=0;
void in_out_put()
{
cout<<"input number:";
cin>>n;
while(n>0){
m=m*10+n%10;
n=n/10;
}
cout<<m<<endl;
}
};
int main(){
rollback n;
n.in_out_put();
}