/*test1：斐波那契数列（控制流 + 函数调用）*/
fn fib(n:i32) -> i32 {
    if n < 1 {
        return n;
    } else {
        return fib(n - 1) + fib(n - 2);
    }
}

fn main() {
    i32 x;
    i32 y;
    x = 5 * 2 + 2;
    a = 2 == 2;
    x = fib(6);
    return x;
}