//uva10268 #include <bits/stdc++.h> using namespace std; int main() { long long int x, x1, temp; char c; vector<long long int> a; while (scanf("%lld",&x)!=EOF) { while (scanf("%lld%c",&temp, &c)) { if (c!=' ') break; a.push_back(temp); } temp = 0, x1 = 1; for (int i = a.size()-1, j = 1; i>=0; i--, j++) temp+= a[i]*j*x1, x1*= x; printf("%lld\n", temp); a.clear(); } return 0; }