#include "bits/stdc++.h"
using namespace std;
#define FOR(i,j,k) for(int (i)=(j);(i)<(int)(k);++(i))
#define rep(i,j) FOR(i,0,j)
#define each(x,y) for(auto &(x):(y))
#define mp make_pair
#define all(x) (x).begin(),(x).end()
#define debug(x) cout<<#x<<": "<<(x)<<endl
#define smax(x,y) (x)=max((x),(y))
#define smin(x,y) (x)=min((x),(y))
#define MEM(x,y) memset((x),(y),sizeof (x))
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<ll> vll;

int bitcnt(unsigned int x){
    x = (x & 0x55555555) + (x >> 1 & 0x55555555);
    x = (x & 0x33333333) + (x >> 2 & 0x33333333);
    x = (x & 0x0f0f0f0f) + (x >> 4 & 0x0f0f0f0f);
    x = (x & 0x00ff00ff) + (x >> 8 & 0x00ff00ff);
    x = (x & 0x0000ffff) + (x >> 16 & 0x0000ffff);
    return (int)x;
}

const int N = 14;
vi to[1 << N];
vector<double> pr[1 << N];
double dp[21][1 << N];

int main(){
    int A;
    cin >> A;
    int Y = 80 - A;
    double P0, P1, P2;
    cin >> P0 >> P1 >> P2;
    P0 *= 0.01;
    P1 *= 0.01;
    P2 *= 0.01;
    rep(S, 1 << N){
        bitset<N> b(S);
        FOR(nS, S, 1 << N)if((S&nS)==S){

            bitset<N> nb(nS);
            double p = 1;
            rep(i, N){
                if(b[i])continue;
                if((i == 0||b[i-1]) && (i==N-1 || b[i+1])){
                    if(nb[i])p *= P0;
                    else p *= 1.00 - P0;
                } else if((i == 0 || b[i - 1]) || (i == N - 1 || b[i + 1])){
                    if(nb[i])p *= P1;
                    else p *= 1.00 - P1;
                } else{
                    if(nb[i])p *= P2;
                    else p *= 1.00 - P2;
                }
            }
            to[S].push_back(nS);
            pr[S].push_back(p);
        }
    }

    dp[0][0] = 1;
    rep(y, Y)rep(S, 1 << N){
        rep(i, sz(to[S])){
            int nS = to[S][i];
            double p = pr[S][i];
            dp[y + 1][nS] += dp[y][S] * p;
        }
    }

    double ans = 0;
    rep(S, 1 << N)ans += (N-bitcnt(S))*dp[Y][S];
    cout << setprecision(20) << ans*2 << endl;
}