// vim: set ts=4 sw=4 et tw=80:

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

bool compare_reverse(char* s1, char* s2) {
	const size_t len = strlen(s1);
	if (len != strlen(s2))
		return false;
	for (size_t i = 0; i < len; i++)
		if (s1[i] != s2[len - 1 - i])
			return false;
	return true;
}


int main (const int argc, char** argv) {
	for (int i = 1; i < argc - 1; i++)
		for (int j = i + 1; j < argc; j++)
			if (compare_reverse(argv[i], argv[j]))
				printf("%s %s\n", argv[i], argv[j]);
}