1 1 2 2
1000000000 1000000000
1
 1 1 1000000000 1000000000
100 1000000000
1
 1 1 10 18
5 6
5
 2 1 1000000000 2000000000
111 999999999
101 999999998
1
 4 13 400 600
13 30
1 19
1 160
1 113
58 73 15 319 194 362 128 157 336 162 77 90 96
 1 15 100 200
283 8
30 58 16 45 80 82 55 95 24 23 86 28 51 47 20
 3 2 300 400
24 68
13 65
15 113
127 177
 1 1 2 1
1 10
1
 4 2 7 15
10 9
4 4
9 3
4 10
1 6
 2 1 1000000000 2000000000
111 1000000000
101 1000000000
5
 2 1 1000000000 2000000000
111 999999998
101 999999998
1
 1 1 1000000000 1000000000
1 1000000000
1

1000000000
 -1
 5
 111
 1
 -1
 -1
 -1
 4
 101
 -1
 -1

#define _CRT_SECURE_NO_WARNINGS
#include<iostream>
#include<algorithm>
#include<cmath>
#include<cstdlib>
#include<vector>
#include<string>
#include<map>
#include<set>
#define int long long
using namespace std;
long long pos[100009];

int g[200009];
struct Mystruct
{
	int cost;
	int lt;
};
Mystruct a[200009];
int d[200009];

long long n, k, s, t;
bool Time(int lt)
{
	int time = 0;
	for (int i = 0; i < k + 1; i++)
	{
		if (d[i] > lt)
		{
			return false;
		}
		else 		
		{
			int d1 = 2 * d[i] - lt;
			int d2 = lt - d[i];
			if (d1 > 0)
			{
				time += 2*d1 + d2;
			}
			else
			{
				time += d[i];
			}
		}
	}
	if (time > t)
	{
		return false;
	}
	else
	{
		return true;
	}

}
void main() {
#ifdef _DEBUG
	{
		freopen("input.txt", "r", stdin);
		freopen("output.txt", "w", stdout);
	}
#endif


	cin >> n >> k>>s>>t;
	for (int i = 0; i < n; i++)
	{
		cin >> a[i].cost>>a[i].lt;
	}
	for (int i = 0; i < k; i++)
	{
		cin >> g[i];
	}
	sort(g, g + k);
	d[0] = g[0];
	for (int i = 0; i < k-1; i++)
	{
		d[i + 1] = g[i+1] - g[i];
	}
	d[k] = s - g[k - 1];
	int start = 0, end = 1000000000;
	while (start < end)
	{
		int m = (start + end) / 2;
		if (Time(m))
		{
			end = m;
		}
		else
		{
			start = m + 1;
		}
	}
	int minn = -1;
	for (int i = 0; i < n; i++)
	{
		if (start <= a[i].lt)
		{
			if (minn == -1 || minn > a[i].cost)
			{
				minn = a[i].cost;
			}
		}
	}
	cout << minn;
}