Perform addtion of 3 integers using a function with return type and without argument

int add(void)
{
    int a, b, c;
    scanf("%d %d %d", &a, &b, &c);
    int result = a + b + c;
    return result;
}
int main(void)
{
    int d = add();
    printf("%d", d);
    return 0;
}