void main() {
	const K = readInt;
	const N = readInt;
	int[] A;
	int digitSum(int x) {
		int ret;
		while (x) {
			ret += x % 10;
			x /= 10;
		}
		if (ret > 9) ret = digitSum(ret);
		return ret;
	}
	{
		auto S = new bool[N + 1];
		foreach (i; 2 .. N + 1) {
			if (S[i]) continue;
			if (i >= K) A ~= i;
			for (int j = i * 2; j <= N; j += i) S[j] = true;
		}
	}
	int ans, s;
	int L, D;
	auto cnt = new int[100];
	foreach (R; 0 .. cast(int)(A.length)) {
		if (++cnt[digitSum(A[R])] == 2) D++;
		while (D) if (--cnt[digitSum(A[L++])] == 1) D--;
		int x = R - L + 1;
		if (chmax(s, x)) ans = A[L];
		else if (x == s) chmax(ans, A[L]);
	}
	ans.writeln;
}

import std,core.bitop;
string[]_R;
string readString(){while(_R.empty){_R=readln.chomp.split;}auto ret=_R.front;_R.popFront;return ret;}
int readInt(){return readString.to!int;}
long readLong(){return readString.to!long;}
ulong readULong(){return readString.to!ulong;}
real readReal(){return readString.to!real;}
bool chmin(T)(ref T A,T B){if(A>B){A=B;return true;}else{return false;}}
bool chmax(T)(ref T A,T B){if(A<B){A=B;return true;}else{return false;}}
int lowerBound(T)(T[]A,T x){int L=-1,R=cast(int)A.length;while(R-L>1){int mid=(L+R)/2;(A[mid]<x?L:R)=mid;}return R;}
int upperBound(T)(T[]A,T x){int L=-1,R=cast(int)A.length;while(R-L>1){int mid=(L+R)/2;(A[mid]<=x?L:R)=mid;}return R;}