/* Problem URL: https://cses.fi/problemset/task/1746 */

#include <bits/stdc++.h>

using namespace std;

#define V vector

#define rmin(a, b) a = min(a, b)
#define rmax(a, b) a = max(a, b)

#define rep(i, lim) for (size_t i = 0; i < (lim); i++)
#define nrep(i, s, lim) for (size_t i = s; i < (lim); i++)

#define repv(i, v) for (auto &i : (v))
#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
#define sortv(v) sort(v.begin(), v.end())
#define all(v) (v).begin(), (v).end()

using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using vvvvi = vector<vvvi>;

using ll = long long;

using vl = vector<ll>;
using vvl = vector<vl>;
using vvvl = vector<vvl>;
using vvvvl = vector<vvvl>;

template<class v>
auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
    os << vec[0];
    for (size_t i = 1; i < vec.size(); i++) {
        os << ' ' << vec[i];
    }
    os << '\n';
    return os;
}

template<class v>
auto operator>>(istream &is, vector<v> &vec)->istream& {
    for (auto &i : vec) {
        is >> i;
    }
    return is;
}

template<class v>
auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
    for (auto &i : vec) {
        os << i[0];
        for (size_t j = 1; j < i.size(); j++) {
            os << ' ' << i[j];
        }
        os << '\n';
    }
    return os;
}

template<class v>
auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
    for (auto &i : vec) {
        for (auto &j : i) {
            is >> j;
        }
    }
    return is;
}

const ll mod = 1e9 + 7;

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int n, m;
    cin >> n >> m;

    vi nums(n);
    cin >> nums;

    vvl dp(n, vl(m + 1, 0));
    if (nums[0] > 0) {
        dp[0][nums[0]] = 1;
    } else {
        fill(dp[0].begin(), dp[0].end(), 1);
        dp[0][0] = 0;
    }

    nrep(i, 1, n) {
        if (nums[i] > 0) {
            ll ans = dp[i - 1][nums[i]];
            if (nums[i] < m) {
                ans += dp[i - 1][nums[i] + 1];
            }
            if (nums[i] > 1) {
                ans += dp[i - 1][nums[i] - 1];
            }
            dp[i][nums[i]] = ans % mod;
            continue;
        }

        for (size_t j = 1; j <= m; j++) {
            dp[i][j] += dp[i - 1][j];
            if (j > 1) {
                dp[i][j] += dp[i - 1][j - 1];
            }
            if (j < m) {
                dp[i][j] += dp[i - 1][j + 1];
            }
            dp[i][j] %= mod;
        }
    }

    cout << accumulate(dp[n - 1].begin(), dp[n - 1].end(), 0LL) % mod << '\n';
}