#include<iostream>

#include<cstdio>

#include<cstring>

#include<algorithm>

#include<cmath>

using namespace std;

int read()

{

    int x=,f=; char ch=getchar();

    while (ch<'' || ch>'') {if (ch=='-') f=-; ch=getchar();}

    while (ch>='' && ch<='') {x=x*+ch-''; ch=getchar();}

    return x*f;

}

int N,a,b,K;

long long ans;

#define MAXN 50000

struct SegmentTreeNode

{

    int data[MAXN<<],son[MAXN<<][],root,sz;

    void Insert(int &rt,int l,int r,int L,int R,int x)

        {

            if (L>R) return;

            if (!rt) rt=++sz;

            if (l==L && R==r) {data[rt]=max(data[rt],x); return;}

            int mid=(l+r)>>;

            if (R<=mid) Insert(son[rt][],l,mid,L,R,x);

            else if (L>mid) Insert(son[rt][],mid+,r,L,R,x);

            else Insert(son[rt][],l,mid,L,mid,x),Insert(son[rt][],mid+,r,mid+,R,x);

        }

    void Query(int rt,int l,int r,int x)

        {

            if (!rt) return;

            data[rt]=max(data[rt],x);

            if (!son[rt][] && !son[rt][]) {ans+=(long long)((r-l+)*data[rt]); return;}

            int mid=(l+r)>>;

            Query(son[rt][],l,mid,data[rt]),Query(son[rt][],mid+,r,data[rt]);

            if (!son[rt][]) ans+=(long long)((mid-l+)*data[rt]);

            if (!son[rt][]) ans+=(long long)((r-mid)*data[rt]);

        }

}SegTree;

#define INF (int)1e9

void Freopen() {freopen("sequence.in","r",stdin);freopen("sequence.out","w",stdout);}

void Fclose() {fclose(stdin);fclose(stdout);}

int main()

{

    //Freopen();

    N=read();

    while (N--)

        a=read(),b=read(),K=read(),

        SegTree.Insert(SegTree.root,,INF,a,b-,K);

    SegTree.Query(SegTree.root,,INF,);

    printf("%lld\n",ans);

    return ;

}