#include <stdio.h>
    void fun(int *ptr1, int *ptr2)
    {
        int temp = *ptr1; *ptr1 = *ptr2; *ptr2 = temp;
    }
    void main()
    {
        int m = 10, n = 12;
        fun(&m, &n);
        printf("%d %d\n", m, n);
    }