N = int(input())
A = list(map(int, input().split()))

cnt = [0] * N
cnt[N-1] = -1
for i in reversed(range(N-1)):
    if A[i] != A[i+1]:
        cnt[i] = cnt[i + 1] + 1

ans = 0
for i in range(N-1):
    ans += A[i] * (cnt[i] + 1)
print(ans)