package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
	"strings"
)

var sc = bufio.NewScanner(os.Stdin)

func nextLine() string {
	sc.Scan()
	return sc.Text()
}

func nextInt() int {
	i, _ := strconv.Atoi(nextLine())
	return i
}

func nextInt64() int64 {
	i, _ := strconv.ParseInt(nextLine(), 10, 64)
	return i
}

func nextUint64() uint64 {
	i, _ := strconv.ParseUint(nextLine(), 10, 64)
	return i
}

func nextFloat() float64 {
	f, _ := strconv.ParseFloat(nextLine(), 64)
	return f
}

func main() {
	sc.Split(bufio.ScanLines)
	n := nextInt()
	m := make([]bool, n)
	for i := range m {
		m[i] = true
	}

	for i := 0; i < n; i++ {
		s := nextLine()
		for i, v := range strings.Split(s, " ") {
			if v != "nyanpass" && v != "-" {
				m[i] = false
			}
		}
	}
	c := 0
	for _, v := range m {
		if v == true {
			c++
		}
	}
	if c != 1 {
		fmt.Println(-1)
		return
	}
	for i, v := range m {
		if v == true {
			fmt.Println(i + 1)
			return
		}
	}
}