#include <iostream>

typedef long long ll;
typedef double lf;

// #define DEBUG 1
struct IO
{
    #define MAXSIZE (1 << 20)
    #define isdigit(x) (x >= '0' && x <= '9')
    char buf[MAXSIZE], *p1, *p2;
    char pbuf[MAXSIZE], *pp;
    #if DEBUG
    #else
    IO() : p1(buf), p2(buf), pp(pbuf) {}
    ~IO() {fwrite(pbuf, 1, pp - pbuf, stdout);}
    #endif
    #define gc() (p1 == p2 && (p2 = (p1 = buf) + fread(buf, 1, MAXSIZE, stdin), p1 == p2) ? ' ' : *p1++)
    #define blank(x) (x == ' ' || x == '\n' || x == '\r' || x == '\t')

    template <typename T>
    void Read(T &x)
    {
        #if DEBUG
        std::cin >> x;
        #else
        bool sign = 0; char ch = gc(); x = 0;
        for (; !isdigit(ch); ch = gc())
            if (ch == '-') sign = 1;
        for (; isdigit(ch); ch = gc()) x = x * 10 + (ch ^ 48);
        if (sign) x = -x;
        #endif
    }
    void Read(char *s)
    {
        #if DEBUG
        std::cin >> s;
        #else
        char ch = gc();
        for (; blank(ch); ch = gc());
        for (; !blank(ch); ch = gc()) *s++ = ch;
        *s = 0;
        #endif
    }
    void Read(char &c) {for (c = gc(); blank(c); c = gc());}

    void Push(const char &c)
    {
        #if DEBUG
        putchar(c);
        #else
        if (pp - pbuf == MAXSIZE) fwrite(pbuf, 1, MAXSIZE, stdout), pp = pbuf;
        *pp++ = c;
        #endif
    }
    template <typename T>
    void Write(T x)
    {
        if (x < 0) x = -x, Push('-');
        static T sta[35];
        int top = 0;
        do sta[top++] = x % 10, x /= 10; while (x);
        while (top) Push(sta[--top] ^ 48);
    }
    template <typename T>
    void Write(T x, char lst) {Write(x), Push(lst);}
} IO;
#define Read(x) IO.Read(x)
#define Write(x, y) IO.Write(x, y)
#define Put(x) IO.Push(x)

using namespace std;

const int MAXN = 1010, mod = 1e9 + 7;

inline int adu(int x, int y) { return (x += y) >= mod ? x - mod : x; }
inline void add(int &x, int y) { (x += y) >= mod && (x -= mod); }

int n;
int a[MAXN];

struct value
{
    int x, y;
    void operator += (const value &u) { add(x, u.x), add(y, u.y); }
    value operator ! () const { return value{adu(x, y), y}; }
}f[2][80][80][80], ans;

inline void Clear(int p)
{
    for (int i = 0; i <= 75; i++)
        for (int j = i; j <= 75; j++)
            for (int k = j; k <= 75; k++)
                f[p][i][j][k] = {0, 0};
}

int main()
{
    // freopen("A.in", "r", stdin);
    // freopen("A.out", "w", stdout);
    #if DEBUG
    #else
    ios::sync_with_stdio(0), cin.tie(0);
    #endif
    Read(n);
    for (int i = 1; i <= n; i++) Read(a[i]);
    a[0] = -100;
    bool p = 0;
    f[p][0][0][0] = {0, 1};
    for (int i = 1; i <= n; i++)
    {
        Clear(!p);
        for (int u = 0; u <= 75; u++)
            for (int v = u; v <= 75; v++)
                for (int w = v; w <= 75; w++)
                {
                    if (!f[p][u][v][w].y) continue;
                    int x = min(75, u + a[i] - a[i - 1]), y = min(75, v + a[i] - a[i - 1]), z = min(75, w + a[i] - a[i - 1]);
                    f[!p][x][y][z] += f[p][u][v][w];
                    if (x >= 20 && z >= 75) f[!p][0][x][y] += !f[p][u][v][w];
                    else f[!p][x][y][z] += f[p][u][v][w];
                }
        p = !p;
    }
    for (int i = 0; i <= 75; i++)
        for (int j = i; j <= 75; j++)
            for (int k = j; k <= 75; k++)
                ans += f[p][i][j][k];
    cout << ans.x * 2ll % mod << "\n";
    return 0;
}