#include <bits/stdc++.h>
using namespace std;
using LL = long long int;
#define incID(i, l, r) for(int i = (l)    ; i <  (r); ++i)
#define decID(i, l, r) for(int i = (r) - 1; i >= (l); --i)
#define incII(i, l, r) for(int i = (l)    ; i <= (r); ++i)
#define decII(i, l, r) for(int i = (r)    ; i >= (l); --i)
#define inc(i, n)  incID(i, 0, n)
#define dec(i, n)  decID(i, 0, n)
#define inc1(i, n) incII(i, 1, n)
#define dec1(i, n) decII(i, 1, n)
#define inID(v, l, r) ((l) <= (v) && (v) <  (r))
#define inII(v, l, r) ((l) <= (v) && (v) <= (r))
#define PB push_back
#define EB emplace_back
#define MP make_pair
#define FI first
#define SE second
#define FR front()
#define BA back()
#define ALL(v) v.begin(), v.end()
#define RALL(v) v.rbegin(), v.rend()
auto setmin   = [](auto & a, auto b) { return (b <  a ? a = b, true : false); };
auto setmax   = [](auto & a, auto b) { return (b >  a ? a = b, true : false); };
auto setmineq = [](auto & a, auto b) { return (b <= a ? a = b, true : false); };
auto setmaxeq = [](auto & a, auto b) { return (b >= a ? a = b, true : false); };
#define SI(v) static_cast<int>(v.size())
#define RF(e, v) for(auto & e: v)
#define until(e) while(! (e))
#define if_not(e) if(! (e))
#define ef else if
#define UR assert(false)
#define IN(T, ...) T __VA_ARGS__; IN_(__VA_ARGS__);
void IN_() { };
template<typename T, typename ... U> void IN_(T & a, U & ... b) { cin >> a; IN_(b ...); };
template<typename T> void OUT(T && a) { cout << a << endl; }
template<typename T, typename ... U> void OUT(T && a, U && ... b) { cout << a << " "; OUT(b ...); }

// ---- ----

template<typename T> class SegmentTree {
private:
	int n, s;
	vector<T> a;
	function<T(T &, T &)> f;
	T e;
	bool ok;
public:
	SegmentTree() { n = 0; }
	SegmentTree(int nn, function<T(T &, T &)> ff, T ee) { init(nn, ff, ee); }
	void init(int nn, function<T(T &, T &)> ff, T ee) {
		n = nn;
		f = ff;
		e = ee;
		s = 1;
		while(s < n) { s *= 2; }
		a = vector<T>(2 * s, e);
		ok = true;
	}
	void shift(int & p) {
		assert(inID(p, 0, n));
		p += s;
	}
	void apply(int p, function<void(T &)> g) {
		shift(p);
		g(a[p]);
		while(p > 1) {
			p /= 2;
			a[p] = f(a[2 * p], a[2 * p + 1]);
		}
	}
	T fold_ID(int l, int r) {
		assert(ok);
		assert(inII(l, 0, n)); l += s;
		assert(inII(r, 0, n)); r += s; r--;
		T x = e, y = e;
		while(l <= r) {
			if(l % 2 == 1) { x = f(x, a[l]); l++; }
			if(r % 2 == 0) { y = f(a[r], y); r--; }
			l /= 2;
			r /= 2;
		}
		return f(x, y);
	}
	T fold_II(int l, int r) { return fold_ID(l + 0, r + 1); }
	T fold_CI(int l, int r) { return fold_ID(l + 1, r + 1); }
	T fold_CD(int l, int r) { return fold_ID(l + 1, r + 0); }
	const T & operator[](int p) {
		shift(p);
		return a[p];
	}
	T & ref(int p) {
		shift(p);
		ok = false;
		return a[p];
	}
	void update() {
		dec(i, s) { a[i] = f(a[2 * i], a[2 * i + 1]); }
		ok = true;
	}
};
#define OP(s) [&](auto & A, auto & B) { return s; }
#define AP(s) [&](auto & A) { s; }

// ----

auto fl = [](auto a, auto b) { assert(b != 0); return a / b - (a % b != 0 && ((a >= 0) != (b >= 0)) ? 1 : 0); };
auto ce = [](auto a, auto b) { assert(b != 0); return a / b + (a % b != 0 && ((a >= 0) == (b >= 0)) ? 1 : 0); };
auto mo = [](auto a, auto b) { assert(b != 0); a %= b; if(a < 0) { a += abs(b); } return a; };

int main() {
	const int M = 1'200'036, INF = M + 1;
	vector<int> f(M + 1, INF);
	incII(i, 2, M) {
		if_not(f[i] == INF) { continue; }
		for(int j = i; j <= M; j += i) { setmin(f[j], i); }
	}
	
	IN(LL, l, h);
	LL n = h - l + 1;
	if(n < M) {
		vector<int> s(n, INF);
		inc1(i, 100'000) {
			if_not(f[i] == i) { continue; }
			for(LL j = max(2LL, ce(l, i)) * i; j <= h; j += i) { setmin(s[j - l], i); }
		}
		pair<int, LL> ma = { -1, -1 };
		dec(j, n) {
			if(s[j] == INF) { continue; }
			setmax(ma, make_pair(s[j], j + l));
		}
		OUT(ma.SE);
	} else {
		SegmentTree<pair<int, LL>> st(M + 1, OP(max(A, B)), { -1, -1 });
		incII(i, 2, M) { st.ref(i) = { f[i], i }; }
		st.update();
		LL r = 100'000;
		until(r * r <= h) { r--; }
		dec1(i, r) {
			if(i == 1) { UR; }
			if_not(f[i] == i) { continue; }
			assert(ce(h, i) <= M);
			auto ma = st.fold_II(ce(l, i), fl(h, i));
			if(ma.FI >= i) { OUT(ma.SE * i); break; }
		}
	}
	
	/*
	pair<LL, LL> ans = { -1, -1 };
	incII(i_, l, h) {
		LL i = i_;
		incID(j_, 2, i) {
			LL j = j_;
			if(j * j > i) { break; }
			if(i % j == 0) { setmax(ans, make_pair(j, i)); break; }
		}
	}
	OUT(ans);
	*/
}