def oi(): return int(input())
def os(): return input().rstrip()
def mi(): return list(map(int, input().split()))

# import sys
# input = sys.stdin.readline
# import sys
# sys.setrecursionlimit(10**8)
# import pypyjit
# pypyjit.set_param('max_unroll_recursion=-1')
input_count = 0

N = oi()
S = os()
if "404" in S:
    print("Found")
else:
    print("NotFound")