#include <bits/stdc++.h>

using namespace std;

#define FOR(i,a,b) for (int i = (a); i <= (b); i++)
#define FORD(i,a,b) for (int i = (a); i >= (b); i--)
#define REP(i,b) for (int i = 0; i < (b); i++)

typedef long long int ll;
typedef long double ld;

struct pool {
    ll speedmult;
    ld timefilled;
    ll id;
    ll nextId;
    ll prevId;
};

bool operator<(const pool &a, const pool &b) {
    return a.timefilled < b.timefilled || (a.timefilled == b.timefilled && a.id < b.id);
}

pool pools[100001];

int main() {
    ll N, F;
    while(scanf("%lli %lli", &N, &F) == 2) {
        set<pool> s;
        REP(i, N) {
            ll cap;
            scanf("%lli", &cap);
            pools[i] = {1, ((ld)cap)/F, i, i+1, i-1};
            s.insert(pools[i]);
        }
        ld curtime = 0;
        while(!s.empty()) {
            pool curpool = *s.begin();
            s.erase(s.begin());
            
            curtime = curpool.timefilled;
            
            if(curpool.id == N-1) {
                printf("%.8Lf ", curtime);
            }
            
            if(curpool.nextId != N) {
                s.erase(pools[curpool.nextId]);
                //printf("curtime: %Lf\n", curtime);
                //printf("pre: %Lf\n", pools[curpool.nextId].timefilled);
                
                ld oldtimeremain = pools[curpool.nextId].timefilled - curtime;
                //printf("oldtimeremain: %Lf\n", oldtimeremain);
                ll speed = pools[curpool.nextId].speedmult;
                //printf("speed: %lli\n", speed);
                //printf("nextspeed: %lli\n", speed + curpool.speedmult);
                ld newtimeremain = (oldtimeremain * speed * F) / ((speed + curpool.speedmult)*F);
                //printf("newtimeremain: %Lf\n", newtimeremain);
                pools[curpool.nextId].timefilled = curtime + newtimeremain;
                
                //printf("post: %Lf\n", pools[curpool.nextId].timefilled);
                pools[curpool.nextId].speedmult += curpool.speedmult;
                pools[curpool.nextId].prevId = curpool.prevId;
                s.insert(pools[curpool.nextId]);
            }
            
            if(curpool.prevId != -1) {
                s.erase(pools[curpool.prevId]);
                pools[curpool.prevId].nextId = curpool.nextId;
                s.insert(pools[curpool.prevId]);
            }
        }
        printf("%.8Lf\n", curtime);
    }
    return 0;
}


/*
stack<pair<ld, ll>> s;
REP(i, N) {
    ll cap;
    scanf("%i", &cap);
    ld tofill = cap, curtime = 0;
    ll speed = 1;
    //printf("C: %i ", cap);
    while(1) {
        ld timefilled = curtime + (tofill/(speed*F));
        if(s.empty() || s.top().first >= timefilled) {
            if(i == N - 1) {
                printf("%.8Lf ", timefilled);
                if(s.empty()) { printf("%.8Lf", timefilled); break; }
                while(s.size() > 1) s.pop();
                printf("%.8Lf", s.top().first);
                break;
            }
            s.emplace(timefilled, speed);
            //printf("tf: %Lf sp: %i\n", timefilled, speed);
            break;
        }
        ld nexttime = s.top().first;
        tofill -= (nexttime - curtime) * (speed * F);
        //printf("tofill: %Lf\n", tofill);
        speed += s.top().second;
        s.pop();
        curtime = nexttime;
    }
}
*/