#include <bits/stdc++.h>
using namespace std;
int main()
{
    int a;
    cin >> a ;
    if (a<= 15)
        cout << a*a;
    else if(a>=16 && a<=30)
        cout << (a/10)+(a%10);
        else
            cout << (a/10)*(a%10);
    return 0;
}