#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
using namespace std;
long long process_consecutive_U(long long current, int count) {
    for (int i = 0; i < count && current > 1; i++) {
        current /= 2;
    }
    return current;
}
long long process_consecutive_LR(long long current, const string& moves, int start, int end) {
    for (int i = start; i <= end; i++) {
        if (moves[i] == 'L') {
            current = current * 2;
        } else { // 'R'
            current = current * 2 + 1;
        }
    }
    return current;
}
long long solve(int n, long long s, const string& moves) {
    long long current = s;
    int i = 0;
    
    while (i < n) {
        if (moves[i] == 'U') {
            int j = i;
            while (j < n && moves[j] == 'U') {
                j++;
            }
            current = process_consecutive_U(current, j - i);
            i = j;
        }
        else {
            int j = i;
            while (j < n && moves[j] != 'U') {
                j++;
            }
            current = process_consecutive_LR(current, moves, i, j - 1);
            i = j;
        }
    }
    
    return current;
}

int main() {
    int n;
    long long s;
    string moves;
    cin >> n >> s;
    cin >> moves;
    long long result = solve(n, s, moves);
    cout << result << endl;
    
    return 0;
}