Notes

Template in C

Constraints

2 ≤ the number of operands in the expression ≤ 100
1 ≤ the number of operators in the expression ≤ 99
-1 × 109 ≤ values in the stack ≤ 109

Input

An expression is given in a line. Two consequtive symbols (operand or operator) are separated by a space character.

You can assume that +, - and * are given as the operator and an operand is a positive integer less than 106

Output

Print the computational result in a line.

Examples

Input

1 2 +


Output

3


Input

1 2 + 3 4 - *


Output

-3
#include <bits/stdc++.h>
using namespace std;
int main(){
  stack<int>s;
  string c;
  while(cin >> c){
    if(c[0] == '*' || c[0] == '+' || c[0] == '-' || c[0] == '/'){
      int b = s.top();
      s.pop();
      int a = s.top();
      s.pop();
      if(c[0] == '*')s.push(a * b);
      if(c[0] == '+')s.push(a + b);
      if(c[0] == '-')s.push(a - b);
      if(c[0] == '/')s.push(a / b);
    }else{
      int temp = atoi(c.c_str());
      s.push(temp);
    }
  }
  cout << s.top() << endl;
  return 0;
}