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

from sys import stdin

rints = lambda: [int(x) for x in stdin.readline().split()]
rints_2d = lambda n: [tuple(rints()) for _ in range(n)]
get_col = lambda arr, i: [row[i] for row in arr]

n, k, s, t = rints()
a, g = rints_2d(n), sorted(rints()) + [s]
sor = sorted(get_col(a, 1))

be, en, ans = 0, n - 1, float('inf')
while be <= en:
    md = (be + en) >> 1
    fuel, point, time = sor[md], 0, 0

    for i in range(k + 1):
        dist = g[i] - point
        rem = fuel - dist
        if rem < 0:
            time = float('inf')
            break
        else:
            x = min(dist, rem)
            time += x + (dist - x) * 2
        point = g[i]

    if time > t:
        be = md + 1
    else:
        en = md - 1
        ans = min(ans, sor[md])

if ans == float('inf'):
    print(-1)
else:
    out = float('inf')
    for i, j in a:
        if j >= ans:
            out = min(out, i)
    print(out)
