#include<bits/stdc++.h>
#define fi first
#define se second
#define eb emplace_back
#define mp make_pair
using namespace std;
typedef long double ld;
typedef long long ll;
typedef unsigned long long ull;
typedef __int128 i128;
template<typename T,typename U>
T ceil(T x, U y) {return (x>0?(x+y-1)/y:x/y);}
template<typename T,typename U>
T floor(T x, U y) {return (x>0?x/y:(x-y+1)/y);}
template<class T,class S>
bool chmax(T &a,const S b) {return (a<b?a=b,1:0);}
template<class T,class S>
bool chmin(T &a,const S b) {return (a>b?a=b,1:0);}
int popcnt(int x) {return __builtin_popcount(x);}
int popcnt(ll x)  {return __builtin_popcountll(x);}
int topbit(int x) {return (x==0?-1:31-__builtin_clz(x));}
int topbit(ll x)  {return (x==0?-1:63-__builtin_clzll(x));}
int lowbit(int x) {return (x==0?-1:__builtin_ctz(x));}
int lowbit(ll x)  {return (x==0?-1:__builtin_ctzll(x));}

#define int long long
#define rep(i,a,b) for(int i=(a);i<=(b);i++)
#define per(i,a,b) for(int i=(a);i>=(b);i--)
typedef pair<int,int> pii; 
typedef vector<int> vi;
typedef vector<pii> vp;
typedef tuple<int,int,int> tiii;
int read() {
  int x=0,w=1; char c=getchar(); 
  while(!isdigit(c)) {if(c=='-') w=-1; c=getchar();}
  while(isdigit(c)) {x=x*10+(c-'0'); c=getchar();}
  return x*w;
}

const int N=2e5+5;
const ld inf=1e9;
int n,a[N],s[N];
ld ans=inf;

ld avg(int l,int r) {
  return 1.*(s[r]-s[l-1])/(r-l+1);
}
ld work(ld L,int l,int r) {
  if(l==r) return a[l];
  ld pl=avg(l,r-1), pr=avg(l+1,r);
  if(pl<L&&pr<L) return inf;
  else if(pl<L) return max(pr,work(L,l+1,r));
  else if(pr<L) return max(pl,work(L,l,r-1));
  else if(pl<pr) return max(pl,work(L,l,r-1));
  else return max(pr,work(L,l+1,r));
}

signed main() {
  n=read();
  rep(i,1,n) a[i]=read(), s[i]=s[i-1]+a[i];
  rep(l,1,n) rep(r,l+1,n) if(avg(l,r)<=avg(1,n)) chmin(ans,max(avg(1,n),work(avg(l,r),1,n))-avg(l,r));
  printf("%.8Lf\n",ans);
  return 0;
}