Codeforces 584A. Olesya and Rodion Solution

 Solution in C++:

 ///La ilaha illellahu muhammadur rasulullah

///******Bismillahir-Rahmanir-Rahim******///

///AH Tonmoy

///Department of CSE,23rd batch

///Islamic University,Bangladesh

1. #include <bits/stdc++.h>
2. using namespace std;
3. int main()
4. {
5. int n,t,i;
6. cin>>n>>t;
7. if((n==1)&&(t==10))
8. {
9. cout<<"-1"<<endl;
10. return 0;
11. }
12. else if(t==10)
13. {
14. cout<<t;
15. for(i=2; i<n; i++)
16. cout<<"0";
17. }
18. else
19. {
20. cout<<t;
21. for(i=2; i<=n; i++)
22. cout<<"0";
23. }
24. cout<<endl;
25. }