#include <bits/stdc++.h>   using namespace std;   const int maxn = 2 * 1e5 + 100;   vector<int> Prime;   int main() {     Prime.clear();     int n, k;     scanf( %d%d , &n, &k);     int flag = 1;     for (int i = 2; flag && i <= n; i++) {       if (n % i == 0) {         while (n % i == 0) {           Prime.push_back(i);           n /= i;         }         if (n == 1) {           flag = 0;         }         if (n < i && n > 1) {           flag = 0;           Prime.push_back(n);         }       }     }     if (Prime.size() < k) {       cout << -1 << endl;     } else {       for (int i = 0; i < k - 1; i++) {         cout << Prime[i] <<    ;       }       int ans = 1;       for (int i = k - 1; i < Prime.size(); i++) {         ans *= Prime[i];       }       if (ans != 1) {         cout << ans << endl;       }     }     return 0;   }   