#include<bits/stdc++.h>
using namespace std;

#define ll long long
#define cpy(a,b) copy(begin(a),end(a),begin(b))
#define ld long double
#define dot(x) fixed<<setprecision(x)
#define foru(a,b,c) for(ll a=b;a<=c;a++)

ll n,l[25],r[25],w[25],sel[25],top,ans;

bool ok(ll i){
    foru(k,1,top){
        ll j=sel[k];
        if(!(r[j]<l[i]||r[i]<l[j]))return 0;
    }
    return 1;
}

void dfs(ll pos,ll cur){
    if(pos>n){
        ans=max(ans,cur);
        return;
    }
    dfs(pos+1,cur);
    if(ok(pos)){
        sel[++top]=pos;
        dfs(pos+1,cur+w[pos]);
        top--;
    }
}

int main(){
    freopen("sum.in" ,"r",stdin );
    freopen("sum.out","w",stdout);
    ios::sync_with_stdio(false);
    cin.tie(NULL);cout.tie(NULL);
    cin>>n;
    foru(i,1,n){
        cin>>l[i]>>r[i]>>w[i];
    }
    dfs(1,0);
    cout<<ans;
    return 0;
}