#include <bits/stdc++.h>
using namespace std;

int main() {
	int n, k, m, c;cin >> n >> k >> m >> c;
    vector<int>s(k+1),v(k+1);
    for(int i = 0; i < c; i++)
    {
        int x; cin >> x;
        s[x]++;
    }
    int ans = 0;
    v[0] = n;
    for(int i = 1; i <= k; i++)
    {
        v[i] += v[i-1];
        int a = s[i], b = v[i];
        s[i] -= min(a, b);
        v[i] -= min(a, b);
        ans += min(a, b);
        if(i + m < n+1)v[i + m] += min(a, b);
    }
    cout << ans;
}