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#include <cstdio>
#include <cmath>
#include <iostream>
#include <algorithm>
#include <queue>
#include <list>
#include <vector>
#include <map>
#include <set>
#include <string>
#include <cstring>
#include <cassert>
#include <limits.h>

using namespace std;

#define ST first
#define ND second
#define MP make_pair
#define PB push_back

typedef long long LL;
typedef long double LD;

typedef vector<int> VI;
typedef pair<int,int> PII;
#define REP(i,n) for(int i=0;i<(n);i++)
#define FOR(i,a,b) for(VAR(i,a);i<=(b);++i)
#define FORD(i,a,b) for(VAR(i,a);i>=(b);--i)
#define FORE(a,b) for(VAR(a,(b).begin());a!=(b).end();++a)
#define VAR(a,b) __typeof(b) a=(b)
#define SIZE(a) ((int)((a).size()))
#define ALL(x) (x).begin(),(x).end()
#define CLR(x,a) memset(x,a,sizeof(x))
#define ZERO(x) memset(x,0,sizeof(x))
#define S(t,i) scanf("%" ## t, &i)
#define SI(i) scanf("%d", &i)

const int INF=INT_MAX;
const int MAXN=5000+5;

int n;
int m = 1000 * 1000 * 1000 + 7;
int c[MAXN];
int s[5000 + 5];

int cmp (const void * a, const void * b)
{
  return *(int*)a - *(int*)b;
}

int main() {
    ios_base::sync_with_stdio(0);
    
    SI(n);
    
    REP(i, n) {
        SI(c[i]);
    }
    qsort(c, n, sizeof(c[0]), cmp);
    
    if (c[0] != 1) {
        printf("0\n");
        return 0;
    }
    
    int result = 0;
    
    s[0] = 1;
    
//    set<int> sums;
//    sums.insert(-1);
//    sums.insert(0);
    
    
    FOR(i, 0, n - 1) {
//        set<int>::iterator si = sums.end();
        int si = 5000;
//        si--;
        result = (result * 2) % m;
        while (c[i] <= si + 1) {
            int newSi = si + c[i];
            if (newSi > 5000) {
                result = (result + s[si]) % m;
            } else {
                s[newSi] = (s[newSi] + s[si]) % m;
            }
            
            si--;
        }
    }
    
//    sums.erase(-1);
//    sums.erase(0);
//    printf("%ld\n", sums.size());

//    FORE(si, sums) {
//        printf("%d %d\n", *si, s[*si]);
        
//        result = (result + s[*si]) % m;
//    }
    
        FOR(si, 1, 5000) {
    //        printf("%d %d\n", *si, s[*si]);
            
            result = (result + s[si]) % m;
        }
    
    printf("%d\n", result);
    
    return 0;
}