// Author: Teoman Ata Korkmaz
#pragma GCC optimize("O3,unroll-loops,inline")
#include <bits/stdc++.h>
#pragma GCC target("avx,avx2,bmi,bmi2,popcnt")
#define int int_fast64_t
using namespace std;
constexpr int N=1e4+4;
constexpr int MOD=1e9+7;
///////////////////////////////////////////////////////////
int n,l,fact[N];
int32_t dp[N][N];//partition K (i) into N (j)
vector<int> v;
signed main(void){
fact[0]=1;for(int i=1;i<N;i++)fact[i]=(fact[i-1]*i)%MOD;
for(int n=0;n<N;n++)dp[0][n]=1;
for(size_t k=1;k<N;k++){
static size_t n;
for(n=1;n<=k;n++){
dp[k][n]=(dp[k][n-1]+dp[k-n][n-1])%MOD;
}
for(;n<=N;n++){
dp[k][n]=dp[k][n-1];
}
}
cin>>n>>l;
if(n==1){
cout<<l<<endl;
exit(0);
}
v.resize(n);
for(auto& i:v){cin>>i;i--;}
int range_size=0;
for(int i=0;i<n;i++)range_size+=2*v[i]+1;
int ans=0;
for(int start=0;start<n;start++){
for(int stop=0;stop<n;stop++){
if(start==stop)continue;
int step=l-(range_size-v[start]-v[stop]);
//cerr<<"start stop step: "<<start<<" "<<stop<<" "<<step<<endl;
if(step<0)continue;
//cerr<<"yippe"<<endl;
ans+=dp[step][n];//*fact[n-2];
}
}
ans%=MOD;
ans*=fact[n-2];
ans%=MOD;
cout<<ans<<endl;
}
