#include<stdio.h>
void swap(int *x,int *y)
{
    int temp = *x;
    *x = *y;
    *y = temp;
    
}
int main()
{
    int a, b;
    scanf("%d %d", &a, &b);
    if (a < 0 || b < 0){
      printf("Invalid Input\n");
      
     else{ 
      
          swap(&a, &b);
          printf("%d\n%d\n", a, b);
    }
      return 0;
 }