package main

import (
	"fmt"
)

func add(a int, b int, c int) {
    assert(a + b == c)
    fmt.Println(a, "+", b, "=", c)
}

func main() {
    go fmt.Println("hello world?")
    i := 1
    j := 2
    n := 888
    go add(i, j, 3)

    go func() {
        n = 666
        assert(n == 666)
        fmt.Println("----- n = ", n);
    }()

    assert(n == 888)
    fmt.Println("before waiting... n = ", n);
    for i := 1; i <= 10000; i++ {
    }
    assert(n == 666)
    fmt.Println("after waiting... n = ", n);
    
    k := i + j
    assert(k == 3)
}