// Wrongri-La Shower

#include <cstdio>
#include <vector>

typedef std::pair<int,double> Pair;

double P[3]; // 虫歯に「なる」確率
std::vector<Pair> ns[1<<14];
double dp[21][1<<14];

double probability(int prev, int next){
    double res = 1.0;
    for(int i=0;i<14;i++){
        if(!(prev >> i & 1)){continue;}
        
        double p;
        if(i == 0){
            p = P[prev >> 1 & 1];
        }else if(i == 13){
            p = P[prev >> 12 & 1];
        }else{
            p = P[(prev >> i-1 & 1) + (prev >> i+1 & 1)];
        }

        res *= next >> i & 1 ? 1.0-p : p;
    }

    return res;
}

int main(){
    int N;
    scanf("%d", &N);
    N = 80-N;

    scanf("%lf %lf %lf", P, P+1, P+2);
    for(int i=0;i<3;i++){P[i] /= 100;}

    
    for(int i=0;i<1<<14;i++){
        for(int j=0;j<1<<14;j++){
            if((i & j) != j){continue;}

            ns[i].push_back(std::make_pair(j, probability(i, j)));
        }
    }

    dp[0][(1<<14)-1] = 1.0;
    for(int i=0;i<N;i++){
        for(int j=0;j<1<<14;j++){
            for(const auto& p : ns[j]){
                dp[i+1][p.first] += dp[i][j] * p.second;
            }
        }
    }

    double res = 0.0;
    for(int i=0;i<1<<14;i++){
        res += dp[N][i] * __builtin_popcount(i);
    }

    printf("%.12f\n", res * 2);
}