#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
constexpr int N=2e5+5;
int a[N],b[N],x[N],n,tp;
ll sum[N];int st[N];
typedef __int128 I;
int main(){
    std::ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    cin>>n;vector<int> v;
    for(int i=1;i<=n;i++){
        cin>>a[i]>>b[i]>>x[i];
        v.push_back(a[i]),v.push_back(b[i]);
    }
    v.push_back(0);
    sort(v.begin(),v.end());v.erase(unique(v.begin(),v.end()),v.end());
    ll ans=-3e18;
    for(int i=1;i<=n;i++){
        sum[0]-=2*x[i];
        sum[lower_bound(v.begin(),v.end(),a[i])-v.begin()]+=2*x[i];
        sum[lower_bound(v.begin(),v.end(),b[i])-v.begin()]+=2*x[i];
    }
    int m=v.size()-1;
    for(int i=1;i<=m;i++) sum[i]+=sum[i-1];
    st[++tp]=m;
    for(int i=m-1;~i;i--){
        while(tp>1&&I(sum[i]-sum[st[tp]])*(v[st[tp]]-v[st[tp-1]])<=I(sum[st[tp]]-sum[st[tp-1]])*(v[i]-v[st[tp]])) tp--;
        st[++tp]=i;
    }
    for(int i=m;~i;i--){
        auto calc=[&](int w){return sum[i]+sum[w]-v[w]*4ll*v[i];};
        while(tp>1&&calc(st[tp])<=calc(st[tp-1]))tp--;
        ans=max(ans,calc(st[tp]));
    }
    cout<<fixed<<setprecision(10)<<ans/4.0<<'\n';
}