#include <stdio.h>

int shift(int a, int b, char c);
int main(){
	int arr[1000] = {0}; 
	int i = 0;
	char c;
	while((c = getchar()) != '@'){
		if(c >= '0' && c <= '9'){
			arr[++i] = c - '0';
			while((c = getchar()) >= '0' && c <= '9') arr[i] += arr[i] * 10 + c - '0';
		}
		if(c == '+'||c == '-'||c == '*'||c == '/') arr[--i] = shift(arr[i], arr[i + 1], c);	
	}
	printf("%d", arr[i]);
	return 0;
} 

int shift(int a, int b, char c)
{
	if(c == '+') return a + b;
	if(c == '-') return a - b;
	if(c == '*') return a * b;
	if(c == '/') return a / b;
}