s=input()

stack=[0]* len(s)；top=- 1；presign='+'；num=0

for i in range(len(s)):

    if'0'<=s[i]<='9':

        num=num*10+int(s[i])

    if i==len(s)- 1 or s[i] in'+-*/':

        if presign=='+':

            top+=1

            stack[top]=num

        elifpresign=='-':

            top+=1

            stack[top]=-num

        elifpresign=='*':

            top+=1

            stack[top]=stack[top- 1]*num

        else:

            top+=1

            stack[top]=stack[top- 1]//num

        presign=s[i]

        num=0

print(sum(stack))     #sum 函数对 stack 中所有元素求和