Python program to find Number of ways in which participant can take part .
def numberOfWays ( x ) : NEW_LINE INDENT dp = [ ] NEW_LINE dp . append ( 1 ) NEW_LINE dp . append ( 1 ) NEW_LINE for i in range ( 2 , x + 1 ) : NEW_LINE INDENT dp . append ( dp [ i - 1 ] + ( i - 1 ) * dp [ i - 2 ] ) NEW_LINE DEDENT return ( dp [ x ] ) NEW_LINE DEDENT