def wz3():
n, u, v = list(map(int, input().split()))
ls = list(map(int, input().split()))
ls = [v * i - u for i in ls]
cnt = defaultdict(list)
cur = 0
cnt[0].append(-1)
for i, n in enumerate(ls):
cur += n
cnt[cur].append(i)
res = 0
for i, c in cnt.items():
res += c * (c-1) // 2
print(res)
