#include <iostream>
#include <string.h>
#define int long long
using namespace std;
const int P = 1000000007;
inline void Madd(int& x, int y) { (x += y) >= P ? (x -= P) : 0; }
int n;
int dp[2][80][80][80];
int pw[1005];
int x[1005];
signed main() {
    cin >> n;
    for (int i = 1; i <= n; i++) cin >> x[i];
    pw[0] = 1;
    for (int i = 1; i <= n; i++) pw[i] = pw[i - 1] * 2 % P;
    dp[0][0][0][0] = 1;
    int ans = 0;
    for (int i = 1; i <= n; i++) {
        int d = x[i] - x[i - 1];
        memset(dp[1], 0, sizeof dp[1]);
        for (int a = 0; a <= 75; a++) {
            for (int b = 0; b <= 75; b++) {
                for (int c = 0; c <= 75; c++) {
                    if (!dp[0][a][b][c]) 
                        continue;
                    static int f[6];
                    f[0] = max(0ll, a - d), f[1] = max(0ll, b - d), f[2] = max(0ll, c - d);
                    for (int i = 0; i < 5; i++) {
                        f[i + 1] = max(f[i + 1], f[i] + 20);
                        if (i + 3 < 6) 
                            f[i + 3] = max(f[i + 3], f[i] + 75);
                    }
                    Madd(dp[1][f[0]][f[1]][f[2]], dp[0][a][b][c]);
                    int j = 0;
                    while (!f[j]) ++j;
                    Madd(ans, j * dp[0][a][b][c] % P * pw[n - i] % P);
                    Madd(dp[1][f[j]][f[j + 1]][f[j + 2]], dp[0][a][b][c]);
                }
            }
        }
        swap(dp[0], dp[1]);
    }
    cout << (ans << 1) % P << "\n";
    return 0;
}