#pragma GCC optimize ("O3")
#pragma GCC target ("sse4")
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef vector<int> vi;
typedef pair<int, int> pi;
#define debug(x) cerr << #x << ": " << x << endl;
#define debug2(x, y) debug(x) debug(y);
#define repn(i, a, b) for(int i = (int)(a); i < (int)(b); i++)
#define rep(i, a) for(int i = 0; i < (int)(a); i++)
#define all(v) v.begin(), v.end()
#define mp make_pair
#define pb push_back
#define lb lower_bound
#define ub upper_bound
#define fi first
#define se second
#define sq(x) ((x) * (x))
template<class T> T gcd(T a, T b){ return ((b == 0) ? a : gcd(b, a % b)); }
bool prime(ll num){
if(num <= 1) return 0;
for(ll j = 2; (j * j) <= num; j++){
if(num % j == 0) return 0;
}
return 1;
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
//freopen("input.in", "r", stdin);
//freopen("output.out", "w", stdout);
ll a, b;
cin >> a >> b;
int rev = 0;
if(a > b) swap(a, b), rev = 1;
if((a - b) % 2 == 0 && (a - b) / 2 <= 29){
vector<ll> ans;
ll cur = a;
int f = 1;
while(cur <= b){
if(!prime(cur)){
f = 0;
break;
}
ans.pb(cur);
cur += 2;
}
if(f){
cout << ans.size() << endl;
if(rev) reverse(all(ans));
rep(i, ans.size()) cout << ans[i] << " ";
cout << endl;
return 0;
}
}
if(rev) swap(a, b);
rep(i, 2) rep(j, 2){
//i == 0 -> add 2's
//i == 1 -> subtract 2's
//j == 0 -> add 2's
//j == 1 -> subtract 2's
rep(k, 30) rep(l, 30){
if((k + l) <= 28){
int f = 1;
vector<ll> ans1 = {a};
vector<ll> ans2 = {b};
ll a1 = a, b1 = b;
rep(m, k){
if(i) a1 -= 2;
else a1 += 2;
ans1.pb(a1);
if(!prime(a1)){
f = 0;
break;
}
}
if(!f) continue;
rep(m, l){
if(j) b1 -= 2;
else b1 += 2;
ans2.pb(b1);
if(!prime(b1)){
f = 0;
break;
}
}
if(f && prime(abs(a1 - b1))){
cout << ans1.size() + ans2.size() << endl;
reverse(all(ans2));
rep(m, ans1.size()) cout << ans1[m] << " ";
rep(m, ans2.size()) cout << ans2[m] << " ";
cout << endl;
return 0;
}
}
}
}
cout << -1 << endl;
return 0;
}
/*
Things to look out for:
- Integer overflows
- Array bounds
- Special cases
Be careful!
*/
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
4 ms |
384 KB |
Output is correct |
| 2 |
Incorrect |
5 ms |
384 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
5 ms |
384 KB |
Output is correct |
| 2 |
Incorrect |
5 ms |
384 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
5 ms |
384 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
5 ms |
384 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
5 ms |
384 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
5 ms |
384 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Execution timed out |
2063 ms |
384 KB |
Time limit exceeded |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Execution timed out |
2080 ms |
384 KB |
Time limit exceeded |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Execution timed out |
2095 ms |
384 KB |
Time limit exceeded |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Execution timed out |
2099 ms |
384 KB |
Time limit exceeded |
| 2 |
Halted |
0 ms |
0 KB |
- |
