#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int INF = 0x3f3f3f3f;
const ll LINF = 0x3f3f3f3f3f3f3f3fLL;
const double EPS = 1e-8;
const int MOD = 1000000007;
const int dy[] = {1, 0, -1, 0}, dx[] = {0, -1, 0, 1};
const int dy8[] = {1, 1, 0, -1, -1, -1, 0, 1},
          dx8[] = {0, -1, -1, -1, 0, 1, 1, 1};
template <typename T, typename U>
inline bool chmax(T &a, U b) {
  return a < b ? (a = b, true) : false;
}
template <typename T, typename U>
inline bool chmin(T &a, U b) {
  return a > b ? (a = b, true) : false;
}
struct IOSetup {
  IOSetup() {
    cin.tie(nullptr);
    ios_base::sync_with_stdio(false);
    cout << fixed << setprecision(20);
  }
} iosetup;
void solve() {
  int n, k;
  cin >> n >> k;
  if (n % 2 == 0) {
    n += 2;
  } else {
    for (int i = 3; i <= n; i += 2) {
      if (n % i == 0) {
        n += i;
        break;
      }
    }
  }
  --k;
  cout << 2LL * k + n << '\n';
}
int main() {
  int t;
  cin >> t;
  while (t--) solve();
  return 0;
}
