f=open("vaipsis.txt")
k, l, p=[int(s) for s in f.readline().strip().split(" ")]

n1, s1, e1, w1=[int(s) for s in f.readline().strip().split(" ")]
n2, s2, e2, w2=[int(s) for s in f.readline().strip().split(" ")]

w1, l-e1
w2, l-e2

if w1<w2:
  if l-e1>w2:
    kattuvusx=min(l-e1, l-e2)-w2
else: 
  if l-e1>w1:   
    kattuvusx=min(l-e1, l-e2)-w1
    
print(kattuvusx)