import sequtils,strutils,strscans,algorithm,math,future,sets,queues,tables,macros macro unpack*(rhs: seq,cnt: static[int]): auto = let t = genSym(); result = quote do:(let `t` = `rhs`;()) for i in 0..<cnt: result[0][1].add(quote do:`t`[`i`]) template get*():string = stdin.readLine() template times*(n:int,body:untyped): untyped = (for _ in 0..<n: body) template `max=`*(x,y:typed):void = x = max(x,y) template `min=`*(x,y:typed):void = x = min(x,y) proc `+=`[T](x:var set[T],y:T):void = x.incl(y) proc `-=`[T](x:var set[T],y:T):void = x.excl(y) proc `+=`[T](x:var set[T],y:set[T]):void = x = x.union(y) proc `*=`[T](x:var set[T],y:set[T]):void = x = x.intersection(y) proc `-=`[T](x:var set[T],y:set[T]):void = x = x.difference(y) converter toInt8(x:int) : int8 = x.toU8() proc parseDecimal(n:int) : auto = ($n).mapIt(it.ord - '0'.ord) proc getIsPrimes(n:int) :seq[bool] = # [0...n] result = newSeqWith(n+1,true) result[0] = false result[1] = false for i in 2..n.float.sqrt.int : if not result[i]: continue for j in countup(i*2,n,i): result[j] = false proc getPrimes(n:int,start:int = 0):seq[int] = # [2,3,5,...n] let isPrime = getIsPrimes(n) result = @[] for i,p in isPrime: if i < start: continue if p : result &= i proc hash(n:int) : int = result = ($n).mapIt(it.ord - '0'.ord).sum() if result > 9: result = hash(result) # hash は 0,3,6,9にならない (3は一度だけ) => 124578の6が最大だが、大きい方を優先するので途中でbreakはできない let K = get().parseInt N = get().parseInt primes = getPrimes(N,start=K) var L = 0 hashes : set[int8] = {} ans = (prime:0, card:0) for i,p in primes: let h = hash(p) if h in hashes: while h in hashes: hashes -= hash(primes[L]) L += 1 hashes += h if hashes.card >= ans.card: ans.prime = primes[L] ans.card = hashes.card echo ans.prime