int main() { while(cin >> n && n!=0) { for(int i=0;i!=88888889;i++) check[i] = false; float ok = 0.12345678; finish = (pow(10.0,n))*ok; Pos pos; vector<int> init; for(int i=0;i!=n;i++) init.push_back(0); for(int i=0;i!=n;i++) pos.push_back(init); for(int i=0;i!=n;i++) { int in; cin >> in; (pos[i])[0] = in; } int ans = search(pos,n); if(ans==-1) cout << "IMPOSSIBLE" <<endl; else cout << ans <<endl; } system("pause"); return 0; }