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12 7 11 8
. .6
10
12 ( ) 11 ( ) 10 ( ) 9 () )
10 ( ) [AMC82007] ( )
250 5( )
2 ()
7( ) 2 [AMC82007] (
2005 . 1985
65
2005 1985
67.5% ( ) 60% ( ) 50.5% ( ) 30% ( )
43 21 [AMC82007] ( )
.
12
23
4
4() 3( ) 2( ) 1 ()
[AMC82007] (
11 n )
.n
. 6 = 1 + 2 + 3 + 6 = 12
