from collections import deque, defaultdict

N, L, B = map(int, input().split())

S, D = map(int, input().split())

rooms = defaultdict(dict)

bounds = set()

for _ in range(L):
    a, b, x, y = map(int, input().split())
    rooms[a][b] = x, y + 1
    bounds.add(x)
    bounds.add(y + 1)

total = 0

bounds = sorted(bounds)


def piecewise(seq):
    it = iter(seq)
    last = next(it)
    for new in it:
        yield last, new
        last = new


for a, b in piecewise(bounds):
    q = deque([S])
    visited = [0] * L

    while q:
        curr = q.pop()
        visited[curr - 1] = 1
        nbors = rooms[curr].items()

        if curr == D:
            total += b - a
            break

        for n, (la, lb) in nbors:
            if visited[n - 1]:
                continue

            if a >= la and b <= lb:
                q.append(n)

print(total)