poj: 3006

 1 #include <iostream>
 2 #include <stdio.h>
 3 #include <string>
 4 #include <stack>
 5 #include <map>
 6 #include <vector>
 7 #include <algorithm>
 8 using namespace std;
 9 
10 bool isPrime(int n) {
11     if (n == 2) return true;
12     if (n % 2 == 0 || n == 1) return false;
13     for (int i = 3; i*i <= n; ++i) {
14         if (n % i == 0) return false;
15     }
16     return true;
17 }
18 
19 int main()
20 {
21     int a, d, n;
22     while (cin >> a >> d >> n && a && d && n) {
23         while (n) {
24             if (isPrime(a)) n--;
25             if (n == 0) cout << a << endl;
26             a += d;
27         }
28     }
29 
30     return 0;
31 }