#include <bits/stdc++.h>
using namespace std;
int F[60][60], f[60][60], g[60][60], h[60][60], dp[60][60], fac[60], inv[60],
    mod = 1000000007;
int fpow(int a, int b) {
  int ans = 1, t = a;
  while (b) {
    if (b & 1) ans = 1ll * ans * t % mod;
    t = 1ll * t * t % mod;
    b >>= 1;
  }
  return ans;
}
int calc(int n, int m, int a, int b) {
  int ans = 0;
  int cur = 1;
  for (int i = 0; i * a <= n && i * b <= m; i++) {
    ans = (ans + 1ll * dp[n - i * a][m - i * b] * cur % mod * inv[i]) % mod;
    cur = 1ll * cur * (g[a][b] + i) % mod;
  }
  return ans;
}
int main() {
  fac[0] = inv[0] = 1;
  for (int i = 1; i <= 51; i++) {
    fac[i] = 1ll * fac[i - 1] * i % mod;
    inv[i] = fpow(fac[i], mod - 2);
  }
  int n, m;
  scanf("%d%d", &n, &m);
  f[0][1] = 1;
  dp[0][0] = 1;
  for (int i = 1; i <= n; i++) {
    for (int j = n + 1; j >= 1; j--) {
      F[i - 1][j] = (F[i - 1][j + 1] + f[i - 1][j]) % mod;
    }
    for (int j = n + 1; j >= 1; j--) {
      h[i][j] = 0;
      for (int k = 0; k < i; k++) {
        h[i][j] = (h[i][j] + 1ll * F[k][j] * F[i - k - 1][j]) % mod;
      }
      g[i][j] = (h[i][j] - h[i][j + 1] + mod) % mod;
    }
    for (int j = 1; j <= n + 1; j++) {
      for (int x = n; x >= 0; x--) {
        for (int y = n + 1; y >= 0; y--) {
          dp[x][y] = calc(x, y, i, j);
        }
      }
    }
    for (int j = 1; j <= n + 1; j++) {
      f[i][j] = dp[i][j - 1];
    }
  }
  printf("%d\n", f[n][m]);
  return 0;
}
