#include <bits/stdc++.h>
using namespace std;
const long long INF = 1e18;
const unsigned long long base = 2333;
const int maxn = 1e2 + 50;
const int maxm = 1e3 + 50;
const int maxv = 1e6 + 5;
const int mod = 1e9 + 7;
const int ba = 3e5;
long long N, T;
long long dp[maxn][5][5][15];
long long ans = 0;
int main() {
  scanf("%lld", &N);
  scanf("%lld", &T);
  for (long long i = 1; i <= 4; i++) {
    for (long long j = i + 1; j <= 4; j++) {
      dp[2][j][i][0] = 1;
    }
  }
  for (long long i = 3; i <= N; i++) {
    for (long long j1 = 1; j1 <= 4; j1++) {
      for (long long j2 = 1; j2 <= 4; j2++) {
        if (j1 != j2)
          for (long long j3 = 1; j3 <= 4; j3++) {
            if (j2 != j3) {
              for (long long k1 = 0; k1 <= T; k1++) {
                if (i != N) {
                  if (j2 > j1 && j2 > j3)
                    dp[i][j1][j2][k1 + 1] += dp[i - 1][j2][j3][k1];
                  else
                    dp[i][j1][j2][k1] += dp[i - 1][j2][j3][k1];
                } else {
                  if (j2 > j1 && j2 > j3)
                    dp[i][j1][j2][k1 + 1] += dp[i - 1][j2][j3][k1];
                  else if (j2 > j1)
                    dp[i][j1][j2][k1] += dp[i - 1][j2][j3][k1];
                }
              }
            }
          }
      }
    }
  }
  for (long long i = 1; i <= 4; i++) {
    for (long long j = 1; j <= 4; j++) ans += dp[N][i][j][T];
  }
  printf("%lld\n", ans);
  return 0;
}
