import core.thread;
import std.conv, std.stdio, std.string;
import std.algorithm, std.array, std.bigint, std.container, std.math, std.range, std.regex;

//	Input
class EOFException : Throwable { this() { super("EOF"); } }
string[] tokens;
string readToken() { for (; tokens.empty; ) { tokens = readln.split; if (tokens.empty && stdin.eof) throw new EOFException; } auto token = tokens[0]; tokens.popFront; return token; }
int readInt() { return to!int(readToken); }
long readLong() { return to!long(readToken); }
real readReal() { return to!real(readToken); }

//	chmin/chmax
void chmin(T)(ref T t, in T f) { if (t > f) t = f; }
void chmax(T)(ref T t, in T f) { if (t < f) t = f; }

//	Pair
struct Pair(S, T) {
	S x; T y;
	int opCmp(    const Pair p) const { return (x < p.x) ? -1 : (x > p.x) ? +1 : (y < p.y) ? -1 : (y > p.y) ? +1 : 0; }
	int opCmp(ref const Pair p) const { return (x < p.x) ? -1 : (x > p.x) ? +1 : (y < p.y) ? -1 : (y > p.y) ? +1 : 0; }
	string toString() const { return "(" ~ to!string(x) ~ ", " ~ to!string(y) ~ ")"; }
}
auto pair(S, T)(inout(S) x, inout(T) y) { return Pair!(S, T)(x, y); }

//	Array
int binarySearch(T)(in T[] as, in bool delegate(T) test) { int low = -1, upp = as.length; for (; low + 1 < upp; ) { int mid = (low + upp) >> 1; (test(as[mid]) ? low : upp) = mid; } return upp; }
int lowerBound(T)(in T[] as, in T val) { return as.binarySearch((T a) { return (a <  val); }); }
int upperBound(T)(in T[] as, in T val) { return as.binarySearch((T a) { return (a <= val); }); }
T[] unique(T)(in T[] as) { T[] bs; foreach (a; as) if (bs.empty || bs[$ - 1] != a) bs ~= a; return bs; }


immutable M = 14;

int N;
real[3] P;

void main(string[] args) {
	try {
	for (; ; ) {
		N = 80 - readInt;
		foreach (i; 0 .. 3) {
			P[i] = readReal / 100.0;
		}
		
		auto dp = new real[][](N + 1, M + 1);
		foreach (x; 0 .. M + 1) {
			dp[0][x] = x;
		}
		foreach (n; 1 .. N + 1) {
			foreach (m; 0 .. M + 1) {
				auto prob = new real[m];
				foreach (i; 0 .. m) {
					int cnt = 2;
					if (i == 0) {
						--cnt;
					}
					if (i == m - 1) {
						--cnt;
					}
					prob[i] = P[cnt];
				}
				dp[n][m] = 0.0;
				foreach (h; 0 .. 1 << m) {
					real prod = 1.0;
					foreach (i; 0 .. m) {
						prod *= (h & 1 << i) ? (1.0 - prob[i]) : prob[i];
					}
					real sum = 0.0;
					int sz;
					foreach (i; 0 .. m + 1) {
						if (h & 1 << i) {
							++sz;
						} else {
							sum += dp[n - 1][sz];
							sz = 0;
						}
					}
					dp[n][m] += prod * sum;
				}
			}
		}
		
		real ans = dp[N][M];
		ans *= 2;
		writefln("%.10f", ans);
		
	}
	} catch (EOFException) {}
}