# Hello World program in Python

def find_fib_n(num):
    if num < 0:
        return 0
    if num < 1:
        return 1
    if num < 2:
        return 1
    if num < 3:
        return 2
    num_prev = 1
    num = 2
    for i in range (0, num-3):
        temp = num
        num = num + num_prev
        num_prev = temp
    return num

def main():
    num = 4
    print "Fib_num of number", str(num), ":", str(find_fib_n(num))

if __name__=="__main__":
    main()