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#include <algorithm>
#include <cstdio>

#define ll long long

const ll B = 1000000007LL;

using namespace std;

ll s1[5555];
ll s2[5555];

int main(int argc, char** argv) {
  int n;
  int a[5000];

  scanf("%d",&n);
  for(int i=0;i<n;i++) {
    scanf("%d", &(a[i]));
  }

  sort(a, a + n);
  int mx = a[n-1];
  ll* p = s1;
  ll* d = s2;
  if(a[0] == 1) {
    p[1] = 1LL%B;
  }

  for(int i=1;i<n;i++) {
    fill(d, d+(mx+1), 0);
    int v = a[i];
    if(v == 1) {
      d[1] = 1LL%B;
    }
    for(int j=0;j<=mx;j++) {
      d[j] += p[j];
      d[j] %= B;
      if(v <= j+1) {
        if(p[j] > 0) {
          int x = min(mx, j+v);
          d[x] += p[j];
          d[x] %= B;
        }
      }
    }
    ll* t = p;
    p = d;
    d = t;
  }
  ll res = 0LL%B;
  for(int i=0;i<=mx;i++) {
    res += p[i];
    res %= B;
  }
  printf("%lld\n", res);
  return 0;
}