fn add(x : i32, y : i32) -> i32 {
    return x + y;
}

fn sum(x : &[i32]) -> i32 {
    let mut s = 0;
    for i in x.iter() {
        s += i;
    }
    s
}

fn main(){
    let c  = add(5, 10);
    println!("c = {}", c);
    let a : [i32; 4] = [3, 4, 5, 6];
    let sum_of_a = sum(&a);
    println!("Sum is {}", sum_of_a);
}