#include <bits/stdc++.h>
#define EPS 1e-9
#define INF 1070000000LL
#define MOD 1000000007LL
#define fir first
#define foreach(it,X) for(auto it=(X).begin();it!=(X).end();it++)
#define numa(x,a) for(auto x: a)
#define ite iterator
#define mp make_pair
#define rep(i,n) rep2(i,0,n)
#define rep2(i,m,n) for(int i=m;i<(n);i++)
#define pb push_back
#define pf push_front
#define sec second
#define sz(x) ((int)(x).size())
#define ALL( c ) (c).begin(), (c).end()
#define gcd(a,b) __gcd(a,b)
#define mem(x,n) memset(x,n,sizeof(x))
#define endl "\n"
using namespace std;
template <int POS, class TUPLE> void deploy(std::ostream &os, const TUPLE &tuple){}
template <int POS, class TUPLE, class H, class ...Ts> void deploy(std::ostream &os, const TUPLE &t){ os << (POS == 0 ? "" : ", ") << get<POS>(t); deploy<POS + 1, TUPLE, Ts...>(os, t); }
template <class T,class U> std::ostream& operator<<(std::ostream &os, std::pair<T,U> &p){ os << "(" << p.first <<", " << p.second <<")";return os; }
template <class T> std::ostream& operator<<(std::ostream &os, std::vector<T> &v){ int remain = v.size(); os << "{"; for(auto e: v) os << e << (--remain == 0 ? "}" : ", "); return os; }
template <class T> std::ostream& operator<<(std::ostream &os, std::set<T> &v){ int remain = v.size(); os << "{"; for(auto e: v) os << e << (--remain == 0 ? "}" : ", "); return os; }
template <class T, class K> std::ostream& operator<<(std::ostream &os, std::map<T, K> &mp){ int remain = mp.size(); os << "{"; for(auto e: mp) os << "(" << e.first << " -> " << e.second << ")" << (--remain == 0 ? "}" : ", "); return os; }
#define DEBUG1(var0) { std::cerr << (#var0) << "=" << (var0) << endl; }
#define DEBUG2(var0, var1) { std::cerr << (#var0) << "=" << (var0) << ", ";DEBUG1(var1); }
#define DEBUG3(var0, var1, var2) { std::cerr << (#var0) << "=" << (var0) << ", ";DEBUG2(var1,var2); }
#define DEBUG4(var0, var1, var2, var3) { std::cerr << (#var0) << "=" << (var0) << ", ";DEBUG3(var1,var2,var3); }
using ll = long long;
#define TEETH 14
int A;
int goal;
double P[3];
double memo[22][TEETH+1];

inline bool bit_stand(int b, int i){
  return (b&(1<<i)) ? true : false;
}

inline double calc2(int b, int i){
  bool next1 = true;
  bool next2 = true;
  if (i == 0){
    next1 = false;
    next2 = bit_stand(b,i+1);
  }else if (i == TEETH - 1){
    next1 = bit_stand(b,i-1);
    next2 = false;
  }else{
    next1 = bit_stand(b,i+1);
    next2 = bit_stand(b,i-1);
  }
  if (next1 && next2) {
    return P[2];
  }else if (next1 || next2) {
    return P[1];
  }else{
    return P[0];
  }
}

inline double calc(int b, int b2){//b->b2に遷移する確率
  double ret = 1;
  for (int i = 0; i < TEETH; i++) {
    if (bit_stand(b,i) != bit_stand(b2,i)) {//虫歯になりました
      ret *= calc2(b,i);
    }else if(bit_stand(b2,i)){//健康なまま
      ret *= 1 - calc2(b,i);
    }
  }
  return ret;
}

inline vector <int> split(int b){//連続したところを切り出す
  int now = 0;
  vector <int> ret;
  for (int i = 0; i < TEETH; i++) {
    if (bit_stand(b,i)){
      now += 1;
    }else{
      if (now > 0) {
        ret.pb(now);
        now = 0;
      }
    }
  }
  if (now > 0) {
    ret.pb(now);
  }
  return ret;
}

double dp_go(int now, int now_teeth){
  if (now == goal) {
    return now_teeth;
  }
  if (memo[now][now_teeth] >= 0) {
    return memo[now][now_teeth];
  }
  double ret = 0;
  int bit = (1 << now_teeth) - 1;
  for(int T=bit; T>0; T=(T-1)&bit){ //TはSの部分集合(S含む、0含まない)
    auto p = calc(bit,T);
    auto seq = split(T);
    numa(x,seq){
      ret += p * dp_go(now+1,x);
    }
  }
  return memo[now][now_teeth] = ret;
}

int main()
{
  cin.tie(0);
  ios_base::sync_with_stdio(0);
  cin >> A;
  rep(i,3){
    cin >> P[i];
    P[i] /= 100;
  }

  rep(i,22){
    rep(j,TEETH+1){
      memo[i][j] = -1;
    }
  }
  goal = 80-A;
  //上下の歯は独立と考えて良い 
  cout << fixed << setprecision(10) << 2 * dp_go(0,TEETH) << endl;
  return 0;
}