f91

#include <bits/stdc++.h>

int f91(int a){

    if(a >= 101) return a-10;

    return f91(f91(a+11));
}

int main() {

    while(true){
        int n; scanf("%d", &n);

        if(n == 0) break;

        printf("f91(%d) = %d\n", n, f91(n));
    }


    return 0;
}