#include <bits/stdc++.h> using namespace std; #define int long long const int mod = 1e9 + 7; class mst { int n; vector <vector <int>> tree; void build(int num, int l, int r, vector <int> &val) { if (l == r - 1) { tree[num].push_back(val[l]); return; } int med = (l + r) / 2; build(2 * num + 1, l, med, val); build(2 * num + 2, med, r, val); merge(tree[2 * num + 1].begin(), tree[2 * num + 1].end(), tree[2 * num + 2].begin(), tree[2 * num + 2].end(), back_inserter(tree[num])); } int get(int num, int l, int r, int low, int high, int v) { if (l >= low && r <= high) { return r - l - (int)(lower_bound(tree[num].begin(), tree[num].end(), v) - tree[num].begin()); } int med = (l + r) / 2; int ans = 0; if (med > low) { ans += get(2 * num + 1, l, med, low, high, v); } if (med < high) { ans += get(2 * num + 2, med, r, low, high, v); } return ans; } int get_ind(int num, int l, int r, int low, int high) { if (l == r - 1) { if (tree[num].front() >= low && tree[num].front() < high) { return l; } return l - 1; } int med = (l + r) / 2; if (lower_bound(tree[2 * num + 2].begin(), tree[2 * num + 2].end(), high) - lower_bound( tree[2 * num + 2].begin(), tree[2 * num + 2].end(), low) > 0) { return get_ind(2 * num + 2, med, r, low, high); } else { return get_ind(2 * num + 1, l, med, low, high); } } public: void init(int nn, vector <int> &val) { n = nn; tree.resize(4 * n); build(0, 0, n, val); } int get(int l, int r, int v) { if (l >= r) { return 0; } return get(0, 0, n, l, r, v); } int get_ind(int mn, int mx) { return get_ind(0, 0, n, mn, mx); } }; void init(vector <int> &val) { for (auto &v : val) { cin >> v; } } bool in(int mask, int i) { return (mask >> i) & 1LL; } int add(int mask, int v) { return mask | (1LL << v); } void solve() { int n; cin >> n; int l = 0; cin >> l; vector <int> val(n); init(val); int dp[(1LL << n)][l + 1][n]; for (int mask = 0; mask < (1LL << n); ++mask) { for (int v = 0; v <= l; ++v) { for (int i = 0; i < n; ++i) { dp[mask][v][i] = 0; } } } for (int i = 0; i < n; ++i) { dp[(1LL << i)][0][i] = 1; } for (int mask = 0; mask < (1LL << n); ++mask) { for (int v = 0; v <= l; ++v) { for (int i = 0; i < n; ++i) { if (in(mask, i)) { for (int j = 0; j < n; ++j) { if (!in(mask, j)) { if (abs(val[i] - val[j]) + v <= l) { dp[add(mask, j)][v + abs(val[i] - val[j])][j] += dp[mask][v][i]; } } } } } } } int ans = 0; for (int i = 0; i < n; ++i) { for (int v = 0; v <= l; ++v) { ans += dp[(1LL << n) - 1][v][i]; } } ans %= mod; cout << ans << '\n'; } signed main() { cin.tie(0); ios::sync_with_stdio(false); solve(); }