#include <stdio.h>

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

int main() {
    int n = 0;
    int a = 3;
    int b = 7;

    swap(&a,&b);
    
    printf("%d,%d",a,b);
}