package main

import (
	"fmt"
)

func main() {
	var n int
	fmt.Scan(&n)
	leaves := make(map[string]bool)
	var species, color string
	for i := 0; i < n; i++ {
		fmt.Scan(&species, &color)
		leaves[species+" "+color] = true
	}
	fmt.Println(len(leaves))
}