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>
#include<cstdio>
using namespace std;

int main(){
  int ans[1000],i=0;
  char ch[1000];
  while(1){
    if(scanf("%s",ch)==EOF)break;

    if(ch[0]!='+'&&ch[0]!='-'&&ch[0]!='*')ans[i]=atoi(ch);
    else {
    if(ch[0]=='+')ans[i-2]+=ans[i-1];
    else if(ch[0]=='-')ans[i-2]-=ans[i-1];
    else if(ch[0]=='*')ans[i-2]*=ans[i-1];
    i-=2;
    }

    i++;
  }
    cout<<ans[0]<<endl;
    return 0;
}