If not prime , copy the largest prime less than current number
if ( p [ ord ( N [ i ] ) - ord ( '0' ) ] == 0 and prevprime [ ord ( N [ i ] ) - ord ( '0' ) ] != 0 ) : NEW_LINE INDENT ans [ ns ] = prevprime [ ord ( N [ i ] ) - ord ( '0' ) ] + ord ( '0' ) ; NEW_LINE small = 1 NEW_LINE ns += 1 NEW_LINE DEDENT