D.cpp

#include<bits/stdc++.h>

using namespace std;

#define double long double

int n, x;
double P[105]; 
double Pmiss[105][100005];
double Pmcur, Phcur;
int guess[105];
double E;

int main() {
		
	cin >> n;

	for(int i=1; i<=n; i++) {
		cin >> x;
		P[i] = x/100.0;
	}
	
	for(int i=1; i<=n; i++) {
		Pmiss[i][1] = 1 - P[i];
		
		for(int j=2; j<=100000; j+=2) {
			Pmiss[i][j] = Pmiss[i][j/2] * Pmiss[i][j/2];
			Pmiss[i][j+1] = Pmiss[i][j] * Pmiss[i][1]; 
		}
	}
	
	E = n * 1.0;
	Phcur = 1.0;
	
	for(int i=1; i<=n; i++) {
		guess[i] = 1;
		Phcur *= P[i];	
	}
	
	int cur = 0;
	
	while(true) {
		E += (1 - Phcur); //Pmisscur
		
		int next = 1;	
		for(int i=2; i<=n; i++) {
			if ((1-Pmiss[i][guess[i]+1]) / (1-Pmiss[i][guess[i]]) > (1-Pmiss[next][guess[next]+1])/(1-Pmiss[next][guess[next]])) next = i;
		}
		
		guess[next]++;
		if (next >= 100000) break;
		
		cur++;
		if (cur > n * 10000) break;
		
		Phcur = 1.0;
		for(int i=1; i<=n; i++) Phcur *= (1-Pmiss[i][guess[i]]);  
	}
	
	for(int i=1; i<=n; i++) E += Pmiss[i][guess[i]] / P[i];
	
	cout << (fixed) << setprecision(9) << E;
}