package main

import (
	"fmt"
)

func pow2(x int) int64 {
	if x < 0 {
		return 0
	}
	return int64(1) << uint(x)
}

func main() {
	var res int64
	var L, N int
	fmt.Scan(&L, &N)
	for i := 0; i < N; i++ {
		var S string
		fmt.Scan(&S)
		res += pow2(L - len(S))
	}
	fmt.Println(res)
}