// Author: Anikait Prasar
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define pb push_back
const ll MOD = 1e9 + 7;
const ll INF = 1e15;
const ll N = 1e6;
ll n, m, k, a, b, c, d, h, l, r, q, x, y;
int rightmostsetbit(ll num) {
if(num==0) {
return -1;
}
for(int j = 0; j<60; j++) {
if((1LL << j) & num) {
return j;
}
}
return 0; // to avoid warning
}
int leftmostsetbit(ll num) {
if(num==0) {
return -1;
}
for(int j = 60; j>=0; j--) {
if((1LL << j) & num) {
return j;
}
}
return 0; // to avoid warning
}
vector<int> adj[N+1];
vector<int> visited(N);
void dfs(int node) {
visited[node] = true;
for(auto j : adj[node]) {
if(!visited[j]) dfs(j);
}
}
vector<int> brr(N);
void solve() {
cin >> n >> m;
vector<pair<int, int>> arr(n);
for(int i = 0; i<n; i++) {
cin >> arr[i].first >> arr[i].second >> x;
}
sort(arr.begin(), arr.end());
int prev = 1;
c = 0;
for(int j = 0; j<n; j++) {
if(prev < arr[j].first) {
c += arr[j].first - prev + 1;
}
prev = max(prev, arr[j].first + arr[j].second);
}
cout << c;
}
/**
----------------------------------------------------
Problem Notes :-
----------------------------------------------------
**/
int main() {
ios::sync_with_stdio(false);
cout.tie(0); cin.tie(0);
int tc = 1;
// cin >> tc;
while(tc--) {
solve();
cout << "\n";
}
return 0;
}
