#include <iostream>

using namespace std;

int n,m;
int dp[100000]={0};

int main()
{
cin>>n>>m;
int i,j,a;
dp[0]=1;
while(n>0)
{
n--;
cin>>a;
for(i=m;i>0;i--)
{
for(j=1;j<=a;j++)
{
if(i-j>=0)
{
dp[i]+=dp[i-j];
}
}
dp[i]=dp[i]%1000007;
}
}
cout<<dp[m]<<endl;
return 0;
}