package main

import (
	"bufio"
	"fmt"
	"os"
)

func main() {
	in := bufio.NewReader(os.Stdin)
	out := bufio.NewWriter(os.Stdout)
	defer out.Flush()

	var n int
	if _, err := fmt.Fscan(in, &n); err != nil {
		return
	}

	type pair struct {
		species string
		color   string
	}
	set := make(map[pair]struct{})

	for i := 0; i < n; i++ {
		var s, c string
		fmt.Fscan(in, &s, &c)
		set[pair{s, c}] = struct{}{}
	}

	fmt.Fprintln(out, len(set))
}