C Global Scope

#include <stdio.h>
int m1 = 5, m2 = 10;//global variable declaration
void add();
int main()
{
int mul;
mul = m1 * m2;
printf("\nMultiplication of %d and %d : %d ", m1, m2, mul);
add();
return 0;
}
void add()
{
int sum;
sum = m1 + m2;
printf("\nSum of %d and %d : %d ", m1, m2, sum);
}