Exercise Function 1

#include <stdio.h>
int addition(int X, int Y);
#include <stdio.h> // library for
int addition(int X, int Y);// function
int main(void) {
 int num1;
 int num2;
 int sum;
printf("Enter variable: ");
scanf("%i%i",&num1,&num2);
sum= addition(num1,num2); //function call
printf("This is the sum: %i",sum);
  return 0;
}
int addition(int X, int Y){ //function definition. This whole string defines addition(int X, int Y);
int result;
result=X+Y;
return result;
}