1 #include <cmath>
2 #include <cstdio>
3 #include <cstring>
4 #include <iostream>
5 #include <algorithm>
6 #define ll long long
7 const int N = 35;
8 using namespace std;
9 int c[23][2]={{0,0},{0,1},{1,1},{1,2},{2,3},{3,5},{5,8},{8,13},{13,21},{21,34},{34,55},{55,89},{89,144},{144,233},{233,377},{377,610},{610,987},{987,1597},{1597,2584},{2584,4181},{4181,6765},{6765,10946},{10946,17711}};
10 int main()
11 {
12 ll a,x,b;
13 while (scanf("%lld%lld%lld",&a,&x,&b)!=EOF)
14 {
15 if ((x-c[a][0])%c[a][1]==0)
16 printf("%lld
",((x-c[a][0])/c[a][1])*c[b][1]+c[b][0]);
17 else cout<<-1<<endl;
18 }
19 return 0;
20 }