def bench(name, f, iters=10000, warmup=3):
    for _ in range(warmup):
        f()
    begin = time.time()
    for _ in range(iters):
        f()
    print(f'{name}: ', (time.time() - begin))
def bench(name, f, iters=10000, warmup=3):
    for _ in range(warmup):
        f()
    begin = time.time()
    for _ in range(iters):
        f()
    print(f'{name}: ', (time.time() - begin))