#include<cstdio>
#include<algorithm>
#include<vector>
#include<cstring>
#include<cmath>
#include<stack>
#include<queue>
#include<string>
#include<iostream>
#include<map>
#include<stdlib.h>
#include<time.h>  
using namespace std;
 
#define sd(a) scanf("%lld",&a)
#define pd(a) printf("%d\n",(a))
#define LL long long
#define F first
#define S second
#define MP make_pair
#define PB push_back
#define mod 1000000007

pair<long long,long long> h[500010];

long long dp[500010];
long long s[500010];

int main()
{
	long long n,m,i,pos;
	sd(n);
	sd(m);
	for(i=1;i<=n;++i)
	{
		sd(h[i].F);
		h[i].S=i;
	}
	h[0]=MP(0,0);
	for(i=2;i<=n;++i)
		h[i].F=h[i-1].F+h[i].F;
	dp[0]=1;
	s[0]=1;
	for(i=1;i<=n;++i)
	{
		pos=(*(lower_bound(h,h+n+1,MP(h[i].F-m,(long long)-1)))).S;
		dp[i]=s[i-1];
		if(pos>0)
			dp[i]=(dp[i]-s[pos-1]+mod)%mod;
		s[i]=(s[i-1]+dp[i])%mod;
	}
	printf("%lld\n",dp[n]);
	
}