太菜了

#include <bits/stdc++.h>
using namespace std;
int main()
{
	int n,r,sum=0;
	cin>>n;
	while(true)
	{
		r=n%10;
		sum = sum*10+r;
		n/=10;

		if(n==0) break;
	}
    				
	cout<<sum<<endl;
	return 0;
}