Lang:G++
Edit1234567891011121314151617181920212223#include <iostream>using namespace std;typedef long long LL;int GCD(LL a,LL b){return b == 0 ? a : GCD(b, a%b);}int main(){LL n; LL k;cin >> n >> k;int cnt = 0;LL tmp = -1;for(int i = 1; i < n; ++i){if(i != 1 && tmp != -1 && i % tmp == 0) continue;if(GCD(i,n) == 1) cnt++;else tmp = i;if(cnt == k){cout << i << endl;break;}}return 0;}