1+ #!usr/bin/env python3
2+ from collections import defaultdict , deque , Counter , OrderedDict
3+ from bisect import bisect_left , bisect_right
4+ from functools import reduce , lru_cache
5+ from heapq import heappush , heappop , heapify
6+
7+ from itertools import *
8+ import math , fractions
9+ import sys , copy
10+
11+ def L (): return sys .stdin .readline ().split ()
12+ def I (): return int (sys .stdin .readline ().rstrip ())
13+ def SL (): return list (sys .stdin .readline ().rstrip ())
14+ def LI (): return [int (x ) for x in sys .stdin .readline ().split ()]
15+ def LI1 (): return [int (x ) - 1 for x in sys .stdin .readline ().split ()]
16+ def LS (): return [list (x ) for x in sys .stdin .readline ().split ()]
17+ def R (n ): return [sys .stdin .readline ().strip () for _ in range (n )]
18+ def LR (n ): return [L () for _ in range (n )]
19+ def IR (n ): return [I () for _ in range (n )]
20+ def LIR (n ): return [LI () for _ in range (n )]
21+ def LIR1 (n ): return [LI1 () for _ in range (n )]
22+ def SLR (n ): return [SL () for _ in range (n )]
23+ def LSR (n ): return [LS () for _ in range (n )]
24+
25+ def perm (n , r ): return math .factorial (n ) // math .factorial (r )
26+ def comb (n , r ): return math .factorial (n ) // (math .factorial (r ) * math .factorial (n - r ))
27+ def powerset (iterable ):
28+ s = list (iterable )
29+ return chain .from_iterable (combinations (s , r ) for r in range (len (s )+ 1 ))
30+
31+ def make_list (n , * args , default = 0 ): return [make_list (* args , default = default ) for _ in range (n )] if args else [default for _ in range (n )]
32+
33+ dire = [[1 , 0 ], [0 , 1 ], [- 1 , 0 ], [0 , - 1 ]]
34+ dire8 = [[1 , 0 ], [1 , 1 ], [0 , 1 ], [- 1 , 1 ], [- 1 , 0 ], [- 1 , - 1 ], [0 , - 1 ], [1 , - 1 ]]
35+ alphabets = "abcdefghijklmnopqrstuvwxyz"
36+ ALPHABETS = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
37+ MOD = 1000000007
38+ INF = float ("inf" )
39+
40+ sys .setrecursionlimit (1000000 )
41+
42+ class UnionFind :
43+ def __init__ (self , N ): self .N , self .group_count , self .root , self .rank = N , N , [- 1 ] * N , [0 ] * N
44+ def __repr__ (self ): return str (self .all_groups ())
45+
46+ def find (self , x ):
47+ while self .root [x ] >= 0 : x = self .root [x ]
48+ return x
49+
50+ def union (self , x , y ):
51+ x , y = self .find (x ), self .find (y )
52+ if x == y : return
53+ if self .rank [x ] > self .rank [y ]: x , y = y , x
54+ self .root [y ] += self .root [x ]
55+ self .root [x ] = y
56+ if self .rank [x ] == self .rank [y ]: self .rank [y ] += 1
57+ self .group_count -= 1
58+
59+ def same (self , x , y ): return self .find (x ) == self .find (y )
60+ def count (self , x ): return - self .root [self .find (x )]
61+ def members (self , x ): return [i for i in range (self .N ) if self .same (x , i )]
62+ def roots (self ): return [i for i , x in enumerate (self .root ) if x < 0 ]
63+ def all_groups (self ):
64+ d = defaultdict (lambda : [])
65+ for i in range (self .N ): d [self .find (i )].append (i )
66+ return dict (d )
67+
68+ def main ():
69+ N , M = LI ()
70+ AB = LIR1 (M )
71+ uf = UnionFind (N )
72+ for a , b in AB : uf .union (a , b )
73+
74+ print (uf .all_groups ())
75+
76+ if __name__ == '__main__' :
77+ main ()
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