#include <stdio.h>


extern long add3(long first, long second, long third);

int main(void)
{
 long tal[3];
 int i = 0;

 while(i < 3) {
	printf("Mata in heltal %d: ",i+1);
  	if(1 != scanf("%ld",&tal[i]))
	   printf("Ett heltal sade jag...Gör om!\n");
	else
	   i++;
 }

 printf("Summan är %ld!\n",add3(tal[0],tal[1],tal[2]));
 return 0;
}