#include<bits/stdc++.h>
using namespace std;
//#define int long long
const int N=1100,M=77,mod=1e9+7;
int n,ans;
int a[N];
int f[2][M][M][M],g[2][M][M][M],id;

void gmod(int &x){
	if(x>=mod) x-=mod;
}

int getval(int x,int y,int z,int pos){
	if(pos<=x) return 0;
	if(pos<=y) return 1;
	if(pos<=z) return 2;
	return 3;
}

signed main(){
	ios::sync_with_stdio(false);
	cin.tie(0);
	cin>>n;
	for(int i=1;i<=n;i++) cin>>a[i];
	
	f[0][75][75][75]=1;
	id=0;
	for(int i=1;i<=n;i++){
		id^=1;
		for(int x=0;x<=75;x++)
			for(int y=min(x+20,75);y<=75;y++)
				for(int z=min(y+20,75);z<=75;z++)
					f[id][x][y][z]=0;
		for(int x=0;x<=75;x++){
			for(int y=min(x+20,75);y<=75;y++){
				for(int z=min(y+20,75);z<=75;z++){
					if(!f[id^1][x][y][z]) continue;
					int pos1=min((a[i]-20)-(a[i-1]-75),75),pos2=min((a[i]-75)-(a[i-1]-75),75);
					int val1=getval(x,y,z,pos1),val2=getval(x,y,z,pos2);
					
					int nx,ny,nz,d=a[i]-a[i-1];
					int ix=x,iy=y,iz=z;
					if(ix==75) ix+=d;
					if(iy==75) iy+=d;
					if(iz==75) iz+=d;
					
					if(val2==0) nx=ix-d,ny=iy-d,nz=iz-d;
					else if(val2==1) nx=iy-d,ny=iz-d,nz=75;
					else if(val2==2) nx=iz-d,ny=75,nz=75;
					else if(val2==3) nx=75,ny=75,nz=75;
					//shift to current position
					
					gmod(f[id][nx][ny][nz]+=f[id^1][x][y][z]);
					gmod(g[id][nx][ny][nz]+=(g[id^1][x][y][z]+1ll*f[id^1][x][y][z]*val2%mod)%mod);
					//0: old base
					//val2: new base
					//do not choose
					
					int val=min(1+val1,3+val2);
					int del=val-val2;
					
					if(del==1) nx=min(nx,74);
					if(del==2) nx=min(nx,74),ny=min(ny,74);
					if(del==3) nx=min(nx,74),ny=min(ny,74),nz=min(nz,74);
					
					gmod(f[id][nx][ny][nz]+=f[id^1][x][y][z]);
					gmod(g[id][nx][ny][nz]+=(g[id^1][x][y][z]+1ll*f[id^1][x][y][z]*val2%mod)%mod);
					gmod(ans+=(g[id^1][x][y][z]+1ll*f[id^1][x][y][z]*val%mod)%mod);
					//choose
				}
			}
		}
	}
	
	cout<<ans*2%mod;
}