package main

import (
	"crypto/rand"
	"encoding/binary"
	"log"
)

func num() int {
	b := make([]byte, 4)
	_, err := rand.Read(b)
	if err != nil {
		log.Fatal(err)
	}
	return int(binary.LittleEndian.Uint32(b))
}

func main() {
	col := make(map[int]bool)
	var count int
	for i := 0; i < 100000000; i++ {
		n := num()
		_, ok := col[n]
		if !ok {
			col[n] = true
		} else {
			count++
		}
	}

	println(count)
}