#!/usr/bin/ python3.8
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines


def yuki9000(stdin):
    print('Hello World!')


def yuki480(stdin):
    N = int(stdin[0])
    print(N * (N + 1) // 2)


def yuki9001(stdin):
    A, B = map(int, stdin[0].split())
    S = stdin[1].rstrip().decode()
    print(A + B, S)


def yuki9002(stdin):
    N = int(stdin[0])
    for i in range(1, N + 1):
        if i % 15 == 0:
            print('FizzBuzz')
        elif i % 3 == 0:
            print('Fizz')
        elif i % 5 == 0:
            print('Buzz')
        else:
            print(i)

def yuki9008(stdin):
    S = sum(map(int, stdin[1]))
    print(S)
    

def main():
    stdin = readlines()
    n = len(stdin)
    if n == 1:
        S = stdin[0].rstrip()
        if S.isdigit():
            import random
            f = random.choice([yuki480, yuki9002])
            f(stdin)
        else:
            yuki9000(stdin)
    if n == 2:
        if len(stdin[0].split()) == 2:
            yuki9001(stdin)
        else:
            yuki9008(stdin)
            

main()