// URL: https://yukicoder.me/problems/no/162

import std.algorithm, std.array, std.bitmanip, std.container, std.conv, std.format,
       std.functional, std.math, std.range, std.traits, std.typecons, std.stdio, std.string;
import std.regex;

version(unittest) {} else
void main()
{
  int A; io.getV(A); A = 80-A;
  double[] P; io.getA(3, P); P[] /= 100;

  auto n = 14;

  auto memo = new double[][](A+1, n+1);
  foreach (y; 0..A+1) memo[y][0] = 0;
  foreach (t; 0..n+1) memo[0][t] = t;

  double calc(int y, int t)
  {
    if (!memo[y][t].isNaN) return memo[y][t];

    auto e = 0.0;
    foreach (i; 0..1<<t) {
      auto p = 1.0;
      foreach (j; 0..t) {
        auto pj = t == 1 ? P[0] : j == 0 || j == t-1 ? P[1] : P[2];
        p *= i.bitTest(j) ? 1-pj : pj;
      }
      auto m = format("%b", i).matchAll("1+");
      e += p * m.map!"cast(int)a[0].length".map!(ti => calc(y-1, ti)).sum;
    }

    return (memo[y][t] = e);
  }

  io.put(calc(A, n)*2);
}

pragma(inline)
{
  import core.bitop : _bsf = bsf, _bsr = bsr, _popcnt = popcnt;
  pure nothrow @nogc @safe
  {
    bool bitTest(T)(T n, size_t i)
      if (isIntegral!T)
    { return (n & (T(1) << i)) != 0; }
    T bitSet(T)(T n, size_t i)
      if (isIntegral!T)
    { return n | (T(1) << i); }
    T bitReset(T)(T n, size_t i)
      if (isIntegral!T)
    { return n & ~(T(1) << i); }
    T bitComp(T)(T n, size_t i)
      if (isIntegral!T)
    { return n ^ (T(1) << i); }
    int bsf(T)(T n)
      if (is(T == int) || is(T == uint))
    { return _bsf(cast(uint)(n)); }
    int bsf(T)(T n)
      if (is(T == long) || is(T == ulong))
    { return _bsf(cast(ulong)(n)); }
    int bsr(T)(T n)
      if (is(T == int) || is(T == uint))
    { return _bsr(cast(uint)n); }
    int bsr(T)(T n)
      if (is(T == long) || is(T == ulong))
    { return _bsr(cast(ulong)n); }
    int popcnt(T)(T n)
      if (is(T == int) || is(T == uint))
    { return _popcnt(cast(uint)n); }
    int popcnt(T)(T n)
      if (is(T == long) || is(T == ulong))
    { return _popcnt(cast(ulong)n); }
  }
}

pure nothrow @nogc @safe
{
  auto bitSubset(bool includeZero = false, T)(T n)
  {
    return BitSubsetRange!(includeZero, T)(n);
  }

  private struct BitSubsetRange(bool includeZero = false, T)
  {
    private T n, i;

    this(T n) { this.n = this.i = n; }
    pure nothrow @nogc @safe
    {
      static if (includeZero) {
        @property T front() const { return i&n; }
        void popFront() { i &= n; i--; }
        bool empty() const { return i < 0; }
      } else {
        @property T front() const { return i; }
        void popFront() { i = (i-1)&n; }
        bool empty() const { return i <= 0; }
      }
    }
  }
}

auto io = IO!()();
import std.stdio;
struct IO(alias IN = stdin, alias OUT = stdout)
{
  import std.meta : allSatisfy;
  import core.stdc.stdlib : exit;

  void getV(T...)(ref T v)
  {
    foreach (ref w; v) get(w);
  }
  void getA(T)(size_t n, ref T v)
    if (hasAssignableElements!T)
  {
    v = new T(n);
    foreach (ref w; v) get(w);
  }
  void getC(T...)(size_t n, ref T v)
    if (allSatisfy!(hasAssignableElements, T))
  {
    foreach (ref w; v) w = new typeof(w)(n);
    foreach (i; 0..n) foreach (ref w; v) get(w[i]);
  }
  void getM(T)(size_t r, size_t c, ref T v)
    if (hasAssignableElements!T && hasAssignableElements!(ElementType!T))
  {
    v = new T(r);
    foreach (ref w; v) getA(c, w);
  }
  template getS(E...)
  {
    void getS(T)(size_t n, ref T v)
    {
      v = new T(n);
      foreach (ref w; v) foreach (e; E) mixin("get(w."~e~");");
    }
  }

  const struct PutConf
  {
    bool newline = true, flush, exit;
    string floatFormat = "%.10f", delimiter = " ";
  }

  void put(alias conf = "{}", T...)(T v)
  {
    mixin("const PutConf c = "~conf~"; putMain!c(v);");
  }
  void putB(alias conf = "{}", S, T)(bool c, S t, T f)
  {
    if (c) put!conf(t);
    else put!conf(f);
  }
  void putRaw(T...)(T v)
  {
    OUT.write(v);
    OUT.writeln;
  }

  private
  {
    dchar[] buf;
    auto sp = (new dchar[](0)).splitter;

    void nextLine()
    {
      IN.readln(buf);
      sp = buf.splitter;
    }
    void get(T)(ref T v)
    {
      if (sp.empty) nextLine();
      v = sp.front.to!T;
      sp.popFront();
    }

    void putMain(PutConf c, T...)(T v)
    {
      foreach (i, w; v) {
        putOne!c(w);
        if (i+1 < v.length) OUT.write(c.delimiter);
      }
      static if (c.newline) OUT.writeln;
      static if (c.flush) OUT.flush();
      static if (c.exit) exit(0);
    }
    void putOne(PutConf c, T)(T v)
    {
      static if (isInputRange!T && !isSomeString!T) putRange!c(v);
      else static if (isFloatingPoint!T) OUT.write(format(c.floatFormat, v));
      else static if (hasMember!(T, "fprint")) v.fprint(OUT);
      else OUT.write(v);
    }
    void putRange(PutConf c, T)(T v)
    {
      auto w = v;
      while (!w.empty) {
        putOne!c(w.front); w.popFront();
        if (!w.empty) OUT.write(c.delimiter);
      }
    }
  }
}