#include <stdio.h>
#include <iostream>

using namespace std;

void exchange(char *a, char *b)
{
char c[] = "ctring";
*c = *a;
*a = *b;
*b = *c;
}

int main()
{
char s1[] = "atring";
char s2[] = "btring";

exchange(s1,s2);
std::cout << s1 << std::endl;
std::cout << s2 << std::endl;

return 0;
}