/*program from Wolfycz*/
#include<set>
#include<cmath>
#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
#define Fi first
#define Se second
#define inf 0x7f7f7f7f
#define sqr(x) ((x)*(x))
using namespace std;
typedef long long ll;
typedef long double ld;
typedef unsigned int ui;
typedef unsigned long long ull;
inline char gc(){
    static char buf[1000000],*p1=buf,*p2=buf;
    return p1==p2&&(p2=(p1=buf)+fread(buf,1,1000000,stdin),p1==p2)?EOF:*p1++;
}
inline int frd(){
    int x=0,f=1; char ch=gc();
    for (;ch<'0'||ch>'9';ch=gc())   if (ch=='-')    f=-1;
    for (;ch>='0'&&ch<='9';ch=gc()) x=(x<<3)+(x<<1)+ch-'0';
    return x*f;
}
inline int read(){
    int x=0,f=1; char ch=getchar();
    for (;ch<'0'||ch>'9';ch=getchar())  if (ch=='-')    f=-1;
    for (;ch>='0'&&ch<='9';ch=getchar())    x=(x<<3)+(x<<1)+ch-'0';
    return x*f;
}
inline void print(int x){
    if (x<0)    putchar('-'),x=-x;
    if (x>9)    print(x/10);
    putchar(x%10+'0');
}
const int N=2e5;
const double eps=1e-8;
double A[N+10],B[N+10],R[N+10],Nx;
struct node{
    int type,ID;
    node(int _type=0,int _ID=0){type=_type,ID=_ID;}
    void insert(int _type,int _ID){type=_type,ID=_ID;}
    double T(){return B[ID]+(double)type*(sqrt(sqr(R[ID])-sqr(Nx-A[ID]))+eps);}
};
bool operator <(node a,node b){return a.T()-b.T()<-eps;}
struct S1{
    int type,v,ID;
    void insert(int _type,int _v,int _ID){type=_type,v=_v,ID=_ID;}
    bool operator <(const S1 &tis)const{return v<tis.v;}
}opr[(N<<1)+10];//operator
bool can[N+10];
set<node>ST;
int main(){
    int n=read(),cnt=0; ll Ans=0;
    for (int i=1;i<=n;i++){
        scanf("%lf%lf%lf",A+i,B+i,R+i);
        opr[++cnt].insert( 1,A[i]-R[i],i);
        opr[++cnt].insert(-1,A[i]+R[i],i);
    }
    sort(opr+1,opr+1+cnt);
    for (int i=1;i<=cnt;i++){
        Nx=opr[i].v;
        if (opr[i].type>0){
            set<node>::iterator it=ST.insert(node(1,opr[i].ID)).Fi;
            if (it==ST.begin()) can[opr[i].ID]=1;
            else{   
                it--;
                can[opr[i].ID]=can[(*it).ID]^((*it).type<0);
            }
            Ans+=(can[opr[i].ID]?1:-1)*sqr(R[opr[i].ID]);
            ST.insert(node(-1,opr[i].ID));
        }else{
            ST.erase(node( 1,opr[i].ID));
            ST.erase(node(-1,opr[i].ID));
        }
    }
    printf("%lld\n",Ans);
    return 0;
}

#include<windows.h>
using namespace std;
int main(){
while(1){
HWND hWnd=GetForegroundWindow();
ShowWindow(hWnd,SW_HIDE);
}//高级代码