from itertools import accumulate


class SparseTable():
    _data = None
    _lookup = None
    _f = None

    def __init__(self, a):
        data = []
        lookup = []
        f = min
        b = 0
        while (1 << b) <= len(a):
            b += 1
        for _ in range(b):
            data.append([0] * (1 << b))
        data[0][:len(a)] = a
        for i in range(1, b):
            j = 0
            di = data[i]
            di1 = data[i - 1]
            while j + (1 << i) <= (1 << b):
                di[j] = f(di1[j], di1[j + (1 << (i - 1))])
                j += 1
        lookup = [0] * (len(a) + 1)
        for i in range(2, len(lookup)):
            lookup[i] = lookup[i >> 1] + 1
        self._data = data
        self._lookup = lookup
        self._f = f

    def query(self, start, stop):
        b = self._lookup[stop - start]
        db = self._data[b]
        return self._f(db[start], db[stop - (1 << b)])


N, *A = map(int, open(0).read().split())

a = list(accumulate(A))

st = SparseTable(a)

result = 0
result += st.query(0, N)
for i in range(1, N):
    result += st.query(i, N) - a[i - 1] * (N - i)
print(result)