#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stdbool.h>

long stack[1024] = {0};
size_t stack_ptr = 0;
bool strict = false;

static void panic(const char *msg) {
	fprintf(stderr, "%s\n", msg);
	exit(EXIT_FAILURE);
}

static bool is(const char *s1, const char *s2) {
	return strcmp(s1, s2) == 0;
}

static long pop(void) {
	if (stack_ptr == 0)
		panic("stack undeflow");
	return stack[--stack_ptr];
}

static void push(long v) {
	if (stack_ptr >= sizeof(stack) / sizeof(stack[0]))
		panic("stack overflow");
	stack[stack_ptr++] = v;
}

#define OP(X) } else if (strcmp(s, X) == 0) {
static void exec(const char *s) {
	if (s[0] >= '0' && s[0] <= '9') {
		push(atol(s));
	OP("drop")
		pop();
	OP("dup")
		const long a = pop();
		push(a); push(a);
	OP("swap")
		const long a = pop();
		const long b = pop();
		push(a); push(b);
	OP("over")
		const long a = pop();
		const long b = pop();
		push(a); push(b); push(a);
	OP("rot")
		const long a = pop();
		const long b = pop();
		const long c = pop();
		push(b); push(a); push(c);
	OP("+")
		push(pop() + pop());
	OP("-")
		const long a = pop();
		push(pop() - a);
	OP("*")
		push(pop() * pop());
	OP("/")
		const long a = pop();
		push(pop() / a);
	OP("%")
		const long a = pop();
		push(pop() % a);
	OP(".s")
		printf("\x1b[94m<%zu> ", stack_ptr);
		for (size_t i = 0; i < stack_ptr; i++)
			printf("%ld ", stack[i]);
		printf("\x1b[0m\n");
	OP(".")
		printf("\x1b[94m%ld\x1b[0m\n", pop());
	} else {
		fprintf(stderr, "unrecognized word '%s'\n", s);
		if (strict)
			exit(EXIT_FAILURE);
	}
}

int main(int argc, char **argv) {
	char line[1024] = {0};
	const char *delim = " \t\n\v\r";

	if (argc > 1 && argv[1][0] == '-' && strchr(argv[1], 's'))
		strict = true;

	while (fgets(line, sizeof(line) - 1, stdin)) {
		char *tok = strtok(line, delim);
		while (tok != NULL) {
			exec(tok);
			tok = strtok(NULL, delim);
		}
	}
	return 0;
}