#define _CRT_SECURE_NO_WARNINGS
#include <bits/stdc++.h>
#define boAshraf { ios_base::sync_with_stdio(false); cin.tie(NULL); }
#define ll long long
#define sz(s) (int)(s).size()
#define endl "\n"
#define ordered_set tree<ll, null_type, less_equal<ll>, rb_tree_tag, tree_order_statistics_node_update>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using namespace std;
void File();
void sol();
const int mod = 1e9 + 7, N = 1e5 + 5;
int add(ll a, ll b) {
    return (0ll + a%mod + b%mod) % mod;
}
int mul(ll a, ll b) {
    return (1LL * a%mod * b%mod) % mod;
}
ll a[N];
int dp1[N][2], dp2[N][3];
ll k;
int rec1(int i, int curr) {
    if (i == 0) return curr;
    int &ret = dp1[i][curr];
    if (~ret) return ret;
    ret = 0;
    if (curr) {
        ret = add(ret, mul(k - 2, rec1(i - 1, curr)));
        ret = add(ret, rec1(i - 1, 0));
    } else {
        ret = add(ret, mul(k - 1, rec1(i - 1, 1)));
    }
    return ret;
}
int rec2(int i, int curr) {
    if (i == 0) return curr != 1;
    int &ret = dp2[i][curr];
    if (~ret) return ret;
    ret = 0;
    if (curr == 0) {
        ret = add(ret, rec2(i - 1, 1));
        ret = add(ret, mul(k - 2, rec2(i - 1, 2)));
    } else if (curr == 1) {
        ret = add(ret, rec2(i - 1, 0));
        ret = add(ret, mul(k - 2, rec2(i - 1, 2)));
    } else {
        ret = add(ret, rec2(i - 1, 0));
        ret = add(ret, rec2(i - 1, 1));
        ret = add(ret, mul(max(0LL,k - 3), rec2(i - 1, 2)));
    }
    return ret;
}
int main() {
    boAshraf
    File();
    int t = 1;
    //cin >> t;
    while (t--) {
        sol();
    }
    return 0;
}
void sol() {
    int n;
    ll l, r;
    cin >> n >> l >> r;
    memset(dp1, -1, sizeof dp1);
    memset(dp2, -1, sizeof dp2);
    for (int i = 0; i < n; ++i) {
        cin >> a[i];
    }
    if (r - l + 1 <= 1) return void (cout << 0);
    k = (r - l + 1);
    int ans = 1;
    int last = 0;
    for (int i = 1; i < n; ++i) {
        if (a[i] == -1) continue;
        if (a[i] == a[last]) {
            ans = mul(ans, rec1(i-last - 1, 0));
        } else {
            ans = mul(ans, rec2(i-last - 1, 0));
        }
        last = i;
    }
    cout << ans << endl;
}

void File() {
#ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif
}