// 河南省实验中学 高中 21级 关天泽

#include <bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define re register

const int INF = 0x3f3f3f3f;
using namespace std;

using namespace std;  
int n, ans = -INF;  
int x[1010], y[1010], c[1010];  
vector<int> d[1010];  
int nc[1010];  
int flag[1010];  

int dfs(int v){  
    flag[v] = 1;  
    nc[v] = c[v];  
    for(re int i = 0; i < d[v].size(); i++){  
        int u = d[v][i];  
        if(flag[u]) continue;  
        dfs(u);
        nc[v] += max(nc[u], 0);  
        ans = max(ans, nc[v]);  
    }  
}  
  
int main(){  
	freopen("subset.in", "r", stdin);
	freopen("subset.out", "w", stdout);
    cin >> n; 
    for(re int i = 0; i < n ;i++){  
        cin >> x[i] >> y[i] >> c[i];  
    }  
    for(re int i = 0; i < n; i++){  
        for(re int j = 0; j < n; j++){  
            if(i == j)continue;  
            if(fabs(x[i] - x[j]) + fabs(y[i] - y[j]) > 1)continue;  
            d[i].push_back(j);  
            d[j].push_back(i);  
        }  
    }  
    dfs(0);  
    cout << ans << endl;
}