#include<stdio.h>

#include<algorithm>

#include<string.h>

#include<stdlib.h>

#include<iostream>

#include<stack>

#include<vector>

using namespace std;

#define LL long long

#define INF 999999999

const int mod = ;

int st[];

int d[];

int pos[];

int dp[];

int main()

{

    int L;

    int S,T,M;

    cin >> L >> S >> T >> M;

    for(int i=;i<=M;i++)

        cin >> pos[i];

    sort(pos+,pos++M);

    for(int i=;i<=M;i++)

        d[i] = (pos[i] - pos[i-])%;

    for(int i=;i<=M;i++)

    {

        pos[i] = pos[i-] + d[i];

        st[pos[i]] = ;

    }

    int n = pos[M];

    for(int i=;i<=n+T;i++)

        dp[i] = M;

    dp[] = ;

    for(int i=;i<=n+T;i++)

    {

        for(int j=S;j<=T;j++)

        {

            if(i >= j)

                dp[i] = min(dp[i],dp[i-j]);

            dp[i] += st[i];

        }

    }

    int ans = M;

    for(int i=n;i<=n+T;i++)

        ans = min(ans,dp[i]);

    cout << ans << endl;

    return ;

}