Задачка про каналы

from sys import stdin
 
 
n = int(input())
line = [(i, 0) for i in range(n)]
 
for s in stdin:
    i, j = map(int, s.split())
    line.extend([(i, -1), (j, 1)])
 
r = n = 0
for v, k in sorted(line):
    if k == 0 and not n:
        r += 1
    else:
        n -= k
    
print(r)

ls = [
  (1, 2),
  (2, 3),
  (5, 6),
]
 
ls += [(i + 1, i + 1) for i in range(6)]
print(ls)
 
result = []
for i, j in ls:
    is_found = False
    for k in result:
        if i in k:
            k.add(j)
            is_found = True
            break
    if not is_found:
        result.append(set((i, j)))
print(result)
 
print(len(result) - 1)

if sum(map(len, result)) == 6:
    print(len(result) - 1)
else:
    pass # [{1, 2, 3}, {1, 5, 6}, {4}]

result = [{1, 2, 3}, {1, 5, 6}, {4}]
 
count = 0
for i in result:
    for j in result:
        if i != j and not bool(i & j):
            count += 1
print(count // 2 - 1)

edges1 = [] 
channels = int(input()) 
p1 = 0 
n = '' 
edges2 = []
while edges2.count(str(channels)) != 1: 
    n = input() 
    edges2 = n.split() 
    edges1.append(edges2)
    
edges3 = [] 
for i in range(len(edges1)): 
    edges3 = edges3 + edges1[i] 
    edges3 = list(dict.fromkeys(edges3)) 
    p2 = 1
    
for j in range(len(edges3)): 
    if int(edges3[j]) == p2: 
        p2 = p2 + 1 
    else: 
        p1 = p1 + 2 
        p2 = p2 + 2 
print(p1)