def gen_fib():
    a, b = 0, 1
    while True:
        yield b
        a, b = b, a + b

def digit_in_fib(n):
    for x in gen_fib():
        print(x)
        s = str(x)
        l = len(s)
        if l >= n:
            return s[n - 1]
        n -= l

print(digit_in_fib(800))