def plus(B, j):
    return B[j + 1] + B[j + 2]
def minus(B, j):
    return B[j + 2] - B[j + 1]

A = input().split()
B = A[::-1]
S = 0
i = 0
for j in range(len(B)):
    if B[j] != '+' and B[j] != '-' and B[j] != '*':
        B[j] = int(B[j])
while i < len(B):
    if B[i] == '+':
        S += plus(B, i)
        i += 3
    elif B[i] == '-':
        S += minus(B, i)
        i += 3
    elif B[i] == '*':
        if B[i + 1] == '+' and B[i + 4] == '+':
            S += plus(B, i + 1) * plus(B, i + 4)
            i += 7
        elif B[i + 1] == '-' and B[i + 4] == '+':
            S += minus(B, i + 1) * plus(B, i + 4)
            i += 7
        elif B[i + 1] == '+' and B[i + 4] == '-':
            S += plus(B, i + 1) * minus(B, i + 4)
            i += 7
        elif B[i + 1] == '-' and B[i + 4] == '-':
            S += minus(B, i + 1) * minus(B, i + 4)
            i += 7
        elif B[i + 2] == '+':
            S += plus(B, i + 2) * B[i + 1]
            i += 5
        elif B[i + 2] == '-':
            S += minus(B, i + 2) * B[i + 1]
            i += 5
    else:
        S += B[i]
        i += 1
print(S)