#include <stdio.h>
#include <string.h>
#include <ctype.h>
#define BUFF_SIZE 100

int stack[100];
int stack_used;
int debug = 1;

int emptystack(){
	if (stack_used == 0) return 1;
	return 0;
}

void initstack(){
	stack_used = 0;
}

void push(int x){
	stack[stack_used] = x;
	stack_used++;
}

int pop(){
	if(emptystack()){
		fprintf(stderr, "##### スタックが空になっています\n");
		return 0;
	}
	stack_used--;
	return stack[stack_used];
}

int top(){
	return stack[stack_used-1];
}

void print_stack(){
	int *s = stack;
	printf("スタックの中身:");
	while(s < &stack[stack_used]){
		printf(" %d", *s);
		s++;
	}
	printf("\n");
}

void space_compile(char *array, int size){
	int i = 0, j, ct;
	while(i < size){
		if(array[i] == ' '){
			ct = 0;
			while(array[i+1+ct] == ' ')
				ct++;
			for(j = i + 1; j < size; j++)
				array[j] = array[j+ct];
			while(ct < 0){
				array[j+ct] = ' ';
				j--;
			}
		}
		i++;
	}
}

int main(){
	int head, next;
	char *input, buf[BUFF_SIZE];
	
	while(1){
		fgets(buf, sizeof(buf), stdin);
		space_compile(buf, sizeof(buf));
		input = buf;

		if(*input == 'q'){
			printf("入力を終了します\n");
			break;
		}

		for(head = 0; head < strlen(input); head = next+1){
			next = head;
			while(input[next] != ' ' && input[next] != '\0')next++;

			if(isdigit(input[head])){
				int num;
				sscanf(&input[head], "%d", &num);
				if(debug) printf("<- %d (数値)\n", num);
				push(num);
			}
			else{
				int num1, num2, answer;
				switch(input[head]){
				case '+':
					if(debug) printf("<- '+' (演算子)\n");
					num1 = pop();
					num2 = pop();
					answer = num2 + num1;
					push(answer);
					break;
				case '-':
					if(debug) printf("<- '-' (演算子)\n");
					num1 = pop();
					num2 = pop();
					answer = num2 - num1;
					push(answer);
					break;
				case '*':
					if(debug) printf("<- '*' (演算子)\n");
					num1 = pop();
					num2 = pop();
					answer = num2 * num1;
					push(answer);
					break;
				case '/':
					if(debug) printf("<- '/' (演算子)\n");
					num1 = pop();
					num2 = pop();
					answer = num2 / num1;
					push(answer);
					break;
				default:
					fprintf(stderr, "##### '%c' は未知の演算子です\n", input[head]);
				}
			}
			if(debug) print_stack();
		}
	}
	printf("答え %d\n", top());
	
	return 0;
}