#include <bits/stdc++.h>
#include "fish.h"
using namespace std;
#define fi first
#define se second
typedef long long ll;
typedef long double ld;
mt19937 rnd(chrono::high_resolution_clock::now().time_since_epoch().count());
ll inf = 1e18;
ll max_weights(int n, int m, vector<int> x, vector<int> y, vector<int> w) {
vector<int> a(n);
for (int i = 0; i < m; i++) {
a[x[i]] = w[i];
}
vector<ll> dp(n, 0);
ll res = 0;
for (int i = 0; i < n; i++) {
ll val = 0;
if (i < n - 1)
val = a[i + 1];
dp[i] = val;
if (i > 0) {
dp[i] = max(dp[i], dp[i - 1] - a[i] + val);
}
if (i > 1) {
dp[i] = max(dp[i], dp[i - 2] + val);
}
if (i > 2) {
dp[i] = max(dp[i], dp[i - 3] + a[i - 1] + val);
}
res = max(res, dp[i]);
}
return res;
}
/*
signed main() {
int n, m;
cin >> n >> m;
vector<int> x(m), y(m), w(m);
for (int i = 0; i < m; i++) {
cin >> x[i] >> y[i] >> w[i];
}
cout << max_weights(n,m,x,y,w) << '\n';
}
*/
