#include<bits/stdc++.h>
//#pragma GCC optimize(3,"Ofast","inline")
//#define int long long
#define i128 __int128
#define ll long long
#define ull unsigned long long
#define uint unsigned int
#define ld double
#define PII pair<int,int>
#define INF 0x3f3f3f3f
#define INFLL 0x3f3f3f3f3f3f3f3f
#define chkmax(a,b) a=max(a,b)
#define chkmin(a,b) a=min(a,b)
#define rep(k,l,r) for(int k=l;k<=r;++k)
#define per(k,r,l) for(int k=r;k>=l;--k)
#define cl(f,x) memset(f,x,sizeof(f))
#define pcnt(x) __builtin_popcount(x)
#define lg(x) (31-__builtin_clz(x))
using namespace std;
void file_IO() {
//	system("fc .out .ans");
	freopen(".in","r",stdin);
	freopen(".out","w",stdout);
}
bool M1;
template<int p>
struct mint {
	int x;
	mint() {
		x=0;
	}
	mint(int _x) {
		x=_x;
	}
	friend mint operator + (mint a,mint b) {
		return a.x+b.x>=p? a.x+b.x-p:a.x+b.x;
	}
	friend mint operator - (mint a,mint b)  {
		return a.x<b.x? a.x-b.x+p:a.x-b.x;
	}
	friend mint operator * (mint a,mint b) {
		return 1ll*a.x*b.x%p;
	}
	friend mint operator ^ (mint a,ll b) {
		mint res=1,base=a;
		while(b) {
			if(b&1)
				res*=base;
			base*=base; b>>=1;
		}
		return res;
	}
	friend mint operator ~ (mint a) {
		return a^(p-2);
	}
	friend mint operator / (mint a,mint b) {
		return a*(~b);
	}
	friend mint & operator += (mint& a,mint b) {
		return a=a+b;
	}
	friend mint & operator -= (mint& a,mint b) {
		return a=a-b;
	}
	friend mint & operator *= (mint& a,mint b) {
		return a=a*b;
	}
	friend mint & operator /= (mint& a,mint b) {
		return a=a/b;
	}
	friend mint operator ++ (mint& a) {
		return a+=1;
	}
	friend mint operator -- (mint& a) {
		return a-=1;
	}
};
const int MOD=1e9+7;
#define mint mint<MOD>
const int N=2e3+5,M=1e2+5,m=75;
mint f[2][M][M][M];
int t[N];
void solve() {
	int n;
	scanf("%d",&n);
	f[0][0][0][0]=1;
	mint res=0;
	rep(i,1,n) {
		scanf("%d",&t[i]);
		int d=t[i]-t[i-1];
		rep(a,0,m) {
			rep(b,0,m) {
				rep(c,0,m)
					f[i&1][a][b][c]=0;
			}
		}
		mint val=mint(2)^(n-i);
		rep(a,0,m) {
			rep(b,0,m) {
				rep(c,0,m) {
					int g[4]={max(a-d,0),max(b-d,0),max(c-d,0),max(a-d,0)+75};
					rep(j,1,3)
						chkmax(g[i],g[i-1]+20);
					f[i&1][g[0]][g[1]][g[2]]+=f[(i-1)&1][a][b][c];
					if(g[0])
						f[i&1][g[0]][g[1]][g[2]]+=f[(i-1)&1][a][b][c];
					else {
						f[i&1][g[1]][g[2]][g[3]]+=f[(i-1)&1][a][b][c];
						res+=f[(i-1)&1][a][b][c]*val;
					}
				}
			}
		}
	}
	printf("%d\n",(res*2).x);
}
bool M2;
signed main() {
	//file_IO();
	int testcase=1;
	//scanf("%d",&testcase);
	while(testcase--)
		solve();
	fprintf(stderr,"used time = %ldms\n",1000*clock()/CLOCKS_PER_SEC);
	fprintf(stderr,"used memory = %lldMB\n",(&M2-&M1)/1024/1024);
	return 0;
}