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#pragma GCC optimize ("O3")
#pragma GCC target ("avx")
#define _DEBUG
//#include <bits/stdc++.h>
#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <climits>
#include <algorithm>
#include <functional>
#include <vector>
#include <set>
#define MAXN 101000
using namespace std;

const size_t TREEND=5;
const size_t TREENN=MAXN*TREEND;
long long int  seg[TREENN]; // neg, pos
long long int lazy[TREENN];  // neg, pos
vector<  pair< pair<int,int> , long long int > > qs; // left, right, height
set< int > test;
vector<int> data;

#define LEFT(i) ((i)<<1)
#define RIGHT(i) ((i)<<1|1)

inline long long int lmax(const long long int &a, const long long int &b) {
    return a>b?a:b;
}

template <class T>
inline T operationOnPull(const T &a, const T &b) {
    return lmax(a , b);
}

template <class T>
inline T operationOnPush(const T &a, const T &b) {
    return operationOnPull<T>(a , b);
}

inline void init(long long int *seg, long long int *lazy) {
    memset(seg, 0x00, sizeof(seg));
    memset(lazy, 0x00, sizeof(lazy));
}

#define IN_RANGE (qL<=L && qR>=R)
#define OO_RANGE (L>=qR || R<=qL)

inline void _push(int lev, long long int seg[], long long int lazy[]) {
    if (!lazy[lev]) return;
    seg[LEFT(lev)] = operationOnPush<long long int>(seg[LEFT(lev)],   lazy[LEFT(lev)] = lmax(lazy[LEFT(lev)]  , lazy[lev]));
    seg[RIGHT(lev)] = operationOnPush<long long int>(seg[RIGHT(lev)], lazy[RIGHT(lev)]= lmax(lazy[RIGHT(lev)] , lazy[lev]));
    lazy[lev] = 0L;
}

// 更新
inline void _pull(int lev, long long int seg[]) {
    seg[lev] = operationOnPull<long long int>(seg[LEFT(lev)] , seg[RIGHT(lev)]);
}

void update(int L, int R, int qL, int qR, int lev, int op, long long int seg[], long long int lazy[]) {
    if (OO_RANGE) return;
    int M = ((unsigned)L+(unsigned)R)>>1;
    if (IN_RANGE) {
        seg[lev] = operationOnPull<long long int>(seg[lev],op);
        lazy[lev] = lmax(lazy[lev], op);
        return;
    }
    _push(lev, seg, lazy);
    update(L, M, qL, qR, LEFT(lev), op, seg, lazy);
    update(M, R, qL,qR, RIGHT(lev),op,seg, lazy);
    _pull(lev, seg);
}

long long int query(int L, int R, int qL, int qR, int flag, long long int seg[], long long int lazy[]) {
    int M=((unsigned)L+(unsigned)R)>>1;
    if (OO_RANGE) return 0; // 沒東西
    if (IN_RANGE) return seg[flag];
    _push(flag, seg, lazy);
    long long int left=0, right=0;
    left = query(L,M,qL,qR,LEFT(flag),seg,lazy);
    right = query(M,R,qL,qR,RIGHT(flag),seg,lazy);
    return lmax(left, right);
}

int main(void){
    int N;
    scanf("%d", &N);
    qs.reserve(N);
    for (int i=0; i<N; ++i) {
        int a, b;
        long long int c;
        scanf("%d%d%lld", &a, &b, &c);
        test.insert(a); test.insert(b);
        qs.push_back( make_pair(make_pair(a,b), c) );
    }
    //sort(qs.begin(), qs.end());
    data.reserve(test.size()+1);
    data.push_back(0);
    int seg_n = test.size();
    for (set<int>::iterator v=test.begin(); v!=test.end(); ++v) {
        data.push_back(*v);
    }
    test.clear();
    //for (const int &v:data) cout << v << endl;
    //for (map<int, int>::iterator v=s.begin(); v!=s.end(); ++v) cout << v->first << ':' << v->second << endl;
    init(seg, lazy);
    for (vector< pair< pair<int,int>, long long int> >::iterator v=qs.begin(); v!=qs.end(); ++v) {
        int left = lower_bound(data.begin(), data.end(), v->first.first)-data.begin();
        int right= lower_bound(data.begin(), data.end(), v->first.second)-data.begin();
        //cout << left << ' ' << right << ' ' << v->second << endl;
        update(1, seg_n, left, right, 1, v->second, seg, lazy);
    }
    long long int sum = 0;
    //cout << "height * width" << endl;
    for (int i=1; i<seg_n; ++i) {
        long long int res = query(1, seg_n, i, i+1, 1, seg, lazy);
        long long int temp = data[i+1]-data[i];
        //cout << res << '*' << temp << endl;
        sum += (res*temp);
    }
    printf("%lld\n", sum);
    return 0;
}