#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int MOD=1e9+7;

int N,D,A,B;
ll m[10];

ll calc(vector<ll>& b){
	ll res=0;
	for(ll x:b)res=(res+(x%MOD)*(x%MOD))%MOD;
	return res;
}

ll dfs(vector<ll> bottles,int day){
	if(day==D)return calc(bottles);
	int n=bottles.size();
	ll best=0;
	vector<int> choose(n,1);
	for(int i=0;i<n-A;i++)choose[i]=0;
	sort(choose.begin(),choose.end());
	do{
		vector<ll> after=bottles;
		for(int i=0;i<n;i++)if(choose[i])after[i]++;
		sort(after.begin(),after.end(),greater<ll>());
		for(int i=0;i<B;i++)if(after[i]>0)after[i]--;
		best=max(best,dfs(after,day+1));
	}while(next_permutation(choose.begin(),choose.end()));
	return best;
}

int main(){
	freopen("Milk.in","r",stdin);
	freopen("Milk.out","w",stdout);
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	cin>>N>>D;
	cin>>A>>B;
	for(int i=0;i<N;i++)cin>>m[i];
	vector<ll> bottles(m,m+N);
	cout<<dfs(bottles,0)<<"\n";
	return 0;
	cout<<0<<"\n";
	return 0;
}