#!/usr/bin/env python3

import sys

def F(n):
    a = 0
    b = 1
    while n > 0:
        c = a
        a = a + b
        b = c
        n = n - 1
    return a

def main():
    for arg in sys.argv[1:]:
        print("F(" + arg + "): " + str(F(int(arg))))

if __name__ == "__main__":
    main()