#include <bits/stdc++.h>   using namespace std;   int main(void) {     int n;     cin >> n;     if (n == 0) {       cout << 1 << endl;       return 0;     }     vector<double> p(n);     vector<int> powers(n, 1);     vector<double> curval(n);     using pdi = pair<double, int>;     priority_queue<pdi, vector<pdi>> q;     double prob = 1.0;     for (int i = 0; i < n; ++i) {       cin >> p[i];       p[i] /= 100.0;       prob *= p[i];       curval[i] = p[i];       q.push(pdi((1 - pow(1 - p[i], powers[i] + 1)) / curval[i], i));     }     double result = n + 1 - prob;     for (int i = 0; i < 500000; ++i) {       auto c = q.top();       q.pop();       prob /= curval[c.second];       ++powers[c.second];       curval[c.second] = 1 - pow(1 - p[c.second], powers[c.second]);       prob *= curval[c.second];       q.push(           pdi((1 - pow(1 - p[c.second], powers[c.second] + 1)) / curval[c.second],               c.second));       result += 1 - prob;     }     cout << fixed << setprecision(20) << result << endl;   }   