#include<cstdio>

int main(){
    unsigned N, M;
    scanf("%u %u", &N, &M);
    unsigned answer = 0;
    if(N < 30 && M > 1U<<(N-1)){
        printf("%u\n", (1U<<N) - 1);
        return 0;
    }
    while(N && M > 1){
        answer += M;
        M = (M+1)>>1;
        N--;
    }
    printf("%u\n", answer + N);
}