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 }