class Solution {
    private:
    long long mod;
    int len;
    int num[int(1e5)];
public:

    int combin(int n,int m){
        long long sum = ((n*(n-1))%mod)/2;
        return sum%mod;
    }
    int purchasePlans(vector<int>& nums, int target) {
        int count=0,mid = target>>1;
        stack<int> s;
        for(int i=0;i<nums.size();i++){
            if(nums[i]<=mid){
                count++;
                num[nums[i]]++;
            }else if(nums[i]<target){
                s.push(target-nums[i]);
            }
        }
        for(int i = 1;i<=mid+1;i++)
            num[i] +=num[i-1];
        long long sum = count>2?combin(count,2):(count==2?1:0);
        while(!s.empty()){
            sum+=num[s.top()];
            s.pop();
            sum%=mod;
        }
        return sum%mod;
    }
    Solution(){
        mod = 1e9 + 7;
        len = 1;
    }
};