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· gph-1
Graph Theory · Handshake lemma
Olympiad classic
●●●●○ 7/10
~4 min
⏱ 0:00
At a party of
9
9
9
people, is it possible that everyone shakes hands with exactly
3
3
3
others? Enter the number of such handshake configurations if impossible, enter
0
0
0
.
handshake-lemma
parity
Submit
Hint 1 of 3
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