#include <bits/stdc++.h>
using namespace std;

int f91(int x)
{
    if(x >= 101) return x-10;
    return f91(f91(x + 11));
}

int main()
{
    int n;
    while(~scanf("%d",&n) && n) {
        printf("f91(%d) = %d\n", n, f91(n));
    }
    return 0;
}