#include "bits/stdc++.h" using namespace std; #define int long long #define FOR(i, a, b) for(int i=(a);i<(b);i++) #define RFOR(i, a, b) for(int i=(b-1);i>=(a);i--) #define REP(i, n) for(int i=0; i<(n); i++) #define RREP(i, n) for(int i=(n-1); i>=0; i--) #define ALL(a) (a).begin(),(a).end() #define UNIQUE_SORT(l) sort(ALL(l)); l.erase(unique(ALL(l)), l.end()); #define CONTAIN(a, b) find(ALL(a), (b)) != (a).end() #define array2(type, x, y) array, x> #define vector2(type) vector > #define out(...) printf(__VA_ARGS__) int dxy[] = {0, 1, 0, -1, 0}; void solve(); signed main() { #if DEBUG std::ifstream in("input.txt"); std::cin.rdbuf(in.rdbuf()); #endif cin.tie(0); ios::sync_with_stdio(false); solve(); return 0; } /*================================*/ int N,M,Q; int P[100]; double F(double n) { double a = 0; double b = 0; REP(i,n) { a += pow(0.81, i+1); b += pow(0.9, i+1); } return sqrt(a)/b; } double f(double n) { double a = F(n) - F(1e6); double b = F(1) - F(1e6); return 1200 * a / b; } double g(double x) { return pow(2.0, x/800); } double invg(double x) { return 800 * log2(x); } void solve() { cin>>N; REP(i,N)cin>>P[i]; double a = 0; double b = 0; REP(i,N) { a += g(P[i])*pow(0.9, i+1); b += pow(0.9, i+1); } double ans = invg(a/b)-f(N); cout << round(ans) << endl; }