package main

import (
    "fmt"
    "math"
    "time"
)

var list = make([]int, 0, 1)

func checkPrime(numero int) {
    var lim = (int)(math.Floor(math.Sqrt(float64(numero))) + 1)

    for j := 0; j < len(list); j++ {
        if numero%list[j] == 0 {
            return
        }
        if list[j] > lim {
            break
        }
    }
        list = append(list,numero)
}

func getPrimes(upperLimit int) {
    for i := 3; i < upperLimit; i += 2 {
        checkPrime(i)
    }
}

func main() {
    benchmakFunction(func() {
        getPrimes(67108864)
    })
    fmt.Println(len(list),list[len(list)-1])
}

func benchmakFunction(functionToBench func()) {
    list = append(list,2)
    fmt.Println(time.Now())
    functionToBench()
    fmt.Println(time.Now())
}