import time
def f1(small, large):
diff = large - small + 1
return diff * (diff + 1) // 2 + diff * (small - 1)
def f2(small, large):
return sum(range(small, large + 1))
#small = int(input())
#large = int(input())
small = 9
large = 999_999_999
t1 = time.time()
r1 = f1(small, large)
t2 = time.time()
t3 = time.time()
r2 = f2(small, large)
t4 = time.time()
print(f"f1 found {r1} in {(t2 - t1) * 1_000_000} us")
print(f"f2 found {r2} in {(t4 - t3) * 1_000_000} us")