#include<bits/stdc++.h>
#define int long long
#define fo(iii,aaa,bbb) for(int iii=aaa;iii<=bbb;iii++)
#define foa(ppp,aaa) for(auto ppp:aaa)
#define pb push_back
#define ls (p<<1)
#define rs (p<<1|1)
#define mid ((l+r)>>1)
#define N (114514)
#define mod (1000000007)
using namespace std;

int n,d,A,B,m[N];

void solve1(){
    sort(m+1,m+n+1);
    int L=n-A+1,R=n-B;
    fo(i,1,d){
        fo(j,L,R)m[j]++;
        sort(m+1,m+n+1);
    }
    int ans=0;
    fo(i,1,n)ans=(ans+((m[i]*m[i])%mod))%mod;
    cout<<ans;
    return;
}

signed main(){
    freopen("Milk.in","r",stdin);freopen("Milk.out","w",stdout);
    ios::sync_with_stdio(0);cin.tie(0);
    cin>>n>>d>>A>>B;
    fo(i,1,n)cin>>m[i];
    if(n<=5000&&d<=5000){
        solve1();
    }
    return 0;
}