Person with 2 is celebrity
MATRIX = [ [ 0 , 0 , 1 , 0 ] , [ 0 , 0 , 1 , 0 ] , [ 0 , 0 , 0 , 0 ] , [ 0 , 0 , 1 , 0 ] ] NEW_LINE def knows ( a , b ) : NEW_LINE INDENT return MATRIX [ a ] [ b ] NEW_LINE DEDENT