package main

import ("fmt"
"time"
)

func find_primes(max int) []int {
    // list of all primes that we find
    var primes []int
    primes = append(primes, 2)

    var is_prime = true
    for i:=3; i<=max; i++ {
        is_prime = false
        // only odds can be prime
        if i%2 != 0 {
            is_prime = true
            // should not be divisible by any previous
            // prime numbers
            for _, x := range primes {
                if i%x == 0 {
                    is_prime = false
                    break
                }
            }
        }
        if is_prime {
            primes = append(primes, i)
        }
    }
    return primes
}

// just sume up all of the primes
func sum_primes(primes []int) int {
    var total int = 0
    for _, x := range primes {
        total = total + x
    }
    return total
}

func main() {
    start := time.Now()
    // find all primes less than 2,000,000
    primes := find_primes(2000000)
    sum := sum_primes(primes)
    fmt.Println(sum)
    t := time.Now()
    elapsed := t.Sub(start)
    fmt.Println(elapsed)
}