# include<iostream> using namespace std; int main(){ int p_1=0, p_2=0, a, n, m, x; cin>>a>>n>>m>>x; p_1=a; for(int i = 3; i <= x; i++){ int l = p_1+p_2; a += p_1+p_2; a -= p_2; p_1 = p_2; p_2 = l; } if(a>=0)cout<<a; else cout<<"No answer."; return 0; }