#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
#define rep(i,l,r) for(int i(l);i<=(r);++i)
#define per(i,r,l) for(int i(r);i>=(l);--i)
#define eb emplace_back
#define Debug(...) fprintf(stderr,__VA_ARGS__)
#define Exit(p) fprintf(stderr,"[exit]: at breakpoint %d\n",p),exit(0);
#define File(filename) freopen(filename ".in","r",stdin),freopen(filename ".out","w",stdout)
template<typename T>void read(T &x){x=0;T flg=1;char ch=getchar();while(!isdigit(ch)){if(ch=='-')flg=-1;ch=getchar();}while(isdigit(ch))x=(x<<3)+(x<<1)+(ch^48),ch=getchar();x*=flg;}
template<typename T,typename... Args>void read(T &x,Args &...args){read(x),read(args...);}
template<typename T>void cmax(T& x,T y){x=max(x,y);}
template<typename T,typename... Args>void cmax(T& x,T y,Args ...args){cmax(x,y);cmax(x,args...);}
template<typename T>void cmin(T& x,T y){x=min(x,y);}
template<typename T,typename... Args>void cmin(T& x,T y,Args ...args){cmin(x,y);cmin(x,args...);}
template<typename T,typename U>ostream &operator<<(ostream &os,const pair<T,U>&x){return os<<"("<<x.first<<","<<x.second<< ")"; };
template<typename T>ostream &operator<<(ostream &os,const vector<T> &as){const int sz=as.size();os<<"[";for(int i=0;i<sz;++i){if(i>=256){os<<",...";break;}if(i>0){os<<",";}os<<as[i];}return os<<"]";}
bool membg=0;

constexpr int N=1e3+7,M=77,mod=1e9+7;
int n,ans,a[N],pwr[N],f[M][M][M],g[M][M][M];
void add(int &x,int y){x+=y-mod;x+=x>>31&mod;}


bool memed=0;
void solve(){
	read(n);
	for(int i=1;i<=n;i++)read(a[i]);
	f[0][0][0]=pwr[0]=1;
	for(int i=1;i<=n;i++)pwr[i]=pwr[i-1]*2%mod;
	for(int i=1;i<=n;i++){
		memcpy(g,f,sizeof(g));
		memset(f,0,sizeof(f));
		int dlt=a[i]-a[i-1];
		for(int x=0;x<M;x++)
			for(int y=0;y<M;y++)
				for(int z=0;z<M;z++)
					if(g[x][y][z]){
						int tx=max(0,x-dlt),ty=max(0,y-dlt),tz=max(0,z-dlt);
						int tmp[4]={tx,ty,tz,0},k=tx==0;
						for(int j=0;j<3;j++){
							tmp[j+1]=max(tmp[j+1],tmp[j]+20);
							if(!j)tmp[j+3]=max(tmp[j+3],tmp[j]+75);
						}
						add(f[tmp[0]][tmp[1]][tmp[2]],g[x][y][z]);
						add(f[tmp[k]][tmp[k+1]][tmp[k+2]],g[x][y][z]);
						add(ans,g[x][y][z]*pwr[n-i]*k);
					}
	}
	printf("%d\n",ans*2%mod);
	return;
}
int main(){
	Debug("%.3lfMB\n",fabs(&memed-&membg)/1024.0/1024.0);
	int timbg=clock();
	int T=1;
	while(T--)solve();
	int timed=clock();
	Debug("%.3lfs\n",1.0*(timed-timbg)/CLOCKS_PER_SEC);
	fflush(stdout);
	return 0;
}