```c
#include <bits/stdc++.h>
using namespace std;
int main(){
// freopen("isbn.in", "r", stdin);
// freopen("isbn.out", "w", stdout);
int n,s;
cin>>n;
while(n) s=s*10+n%10,n/=10;
cout<<s;
//fclose(stdin);
//fclose(stdout);
return 0;
}
```
by AceKnightPuppet @ 2023-10-11 19:51:16