#include <stdio.h>
#include <math.h>

int main(void){
    int L, N, i = 0;
    long long int ans;
    char s;
    scanf("%d %d", &L, &N);
    ans = (long long int)pow(2, L-3) * N;
    while(i<N){
        scanf("%c", &s);
        i++;
    }
    printf("%d\n", ans);
    return 0;
}