#include <iostream>
#include <cstdio>
#include <cstdlib>
using namespace std;
typedef long long ll;

const ll MOD = (ll)(1e9 + 7);
const int N = 500500;
int n;
ll dp[N];
ll sumdp[N];
ll h[N];
ll m;

ll sum(ll x, ll y)
{
    x += y;
    if (x >= MOD) return x - MOD;
    return x;
}
ll sub(ll x, ll y)
{
    x -= y;
    if (x < 0) return x + MOD;
    return x;
}

int main()
{
    scanf("%d%lld", &n, &m);
    for (int i = 1; i <= n; i++)
    {
        scanf("%lld", &h[i]);
        h[i] += h[i - 1];
    }
    dp[0] = 1;
    sumdp[1] = 1;
    int idx = 0;
    for (int i = 1; i <= n; i++)
    {
        while(h[i] - h[idx] > m) idx++;
        dp[i] = sub(sumdp[i], sumdp[idx]);
        sumdp[i + 1] = sum(sumdp[i], dp[i]);
    }
    printf("%lld\n", dp[n]);

    return 0;
}