#include<stdio.h>
void swapByReference(){
     int temp;
     *a = *b;
     *b = temp;
}
int main(){
    int x,y;
    if(scanf("%d\n %d",&x,&y)!=2){
        return 0;
    }
    if(x<0||y<0){
        printf("Invalid Input");
        return 0;
    }
    swapByReference(&x,&y);
    printf("%d\n%d\n",x,y);
    return 0;
}