#include <stdio.h>

void swap(int *a, int *b) {
    int temp = *a;
    *a = *b;
    *b = temp;
}

int main() {
    int x,y;
    scanf("%d", &x);
    scanf("%d", &y);
    
    if (x < 0 || y < 0) {
        printf("Invalid input");
        return 0;
    }
    
    swap(&x, &y);
    
    printf("%d\n")
    return 0;

}