#include <stdio.h>

int calculate_f(int x) {
    if (x > 0) {
        return 1;
    } else if (x == 0) {
        return 0;
    } else {
        return -1;
    }
}

int main() {
    int x;
    scanf("%d", &x);

    int result = calculate_f(x);

    printf("f(%d)=%d\n", x, result);

    return 0;
}