#include<stdio.h>
#include<stdlib.h>
void swap(int *a,int *b){
    int temp =*a;
    *a = *b;
    *b = temp;
}
int main(){
    int d1,d2;
    if(scanf("%d",%d1)!=1 || scanf("%d" ,&d2)!=1){
        printf("Invalid input");
        return 0;
    }
    void(*fp)(int*,int*)=swap;
    fp(&d1,&d2);
    printf("after swap: Distance 1 = %d meters Distance 2 = %d meters",d1,d22);
    return 0;