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 num[100] = {}, index = 0;
	char is[8];
	while(cin >> is){
		if(is[0] == '+'){
			index--;
			num[index-1] += num[index];
		}
		else if(is[0] == '-'){
			index--;
			num[index-1] -= num[index];
		}
		else if(is[0] == '*'){
			index--;
			num[index-1] *= num[index];
		}
		else if(is[0] == '/'){
			index--;
			num[index-1] /= num[index];
		}
		else{
			num[index] = atoi(is);
			index++;
		}
	}
	cout << num[0] << endl;
	return 0;
}
