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 <iostream>
#include <cstdlib>

using namespace std;

int main(){
  int x[100], i = 0;
  char s[100];

  while(1){
    cin >> s;
    if(cin.eof())break;
    if(s[0] == '+'){
      x[i-2] = x[i-2]+x[i-1];
      i--;
    }
    else if(s[0] == '-'){
      x[i-2] = x[i-2]-x[i-1];
      i--;
    }
    else if(s[0] == '*'){
      x[i-2] = x[i-2]*x[i-1];
      i--;
    }
    else {
      x[i] = atoi(s);
      i++;
    }
  }
  cout << x[0] << endl;
  
  

  return 0;
}

