http://poj.org/problem?id=1201
//* @author: ccQ.SuperSupper
import java.io.*;
import java.util.*;
class Intervals{
int left,right,ci;
}
public class Main {
static final int N = 50000+10;
static int DP[] = new int[N],n,left,right;
static Intervals Inter[] = new Intervals[N];
static void start(){
for(int i=0;i< N;++i)
Inter[i] = new Intervals();
}
static int Get_Num(StreamTokenizer cin) throws Exception{
if(cin.nextToken()==StreamTokenizer.TT_EOF)
return -1;
return (int) cin.nval;
}
static int solve(){
int i,j;
boolean flag=true;
for(i=left;i<=right;++i)
DP[i] = -N;
DP[left] = 0;
for(i=left;i<=right && flag;++i){
flag = false;
for(j=0;j< n;++j)if(DP[Inter[j].left]>-N && DP[Inter[j].left]+Inter[j].ci>DP[Inter[j].right]){
DP[Inter[j].right]= DP[Inter[j].left]+Inter[j].ci ;
flag = true;
}
for(j=left;j< right;++j) if(DP[j]>-N && DP[j]>DP[j+1]){
DP[j+1] = DP[j];
flag = true;
}
for(j=right;j>left;--j) if(DP[j]>-N && DP[j]-1>DP[j-1]){
DP[j-1] = DP[j]-1;
flag = true;
}
}
return DP[right];
}
public static void main(String[]args) throws Exception{
int i,j;
start();
StreamTokenizer cin =new StreamTokenizer(new BufferedReader(new InputStreamReader(System.in)));
while((n = Get_Num(cin))>0){
left = N ; right = 0;
for(i=0;i< n;++i){
Inter[i].left = Get_Num(cin);
Inter[i].right = Get_Num(cin)+1;
Inter[i].ci = Get_Num(cin);
left = Min(left,Inter[i].left);
right = Max(right,Inter[i].right);
}
System.out.println(solve());
}
}
static int Max(int a,int b){
return a>b?a:b;
}
static int Min(int a,int b){
return a< b?a:b;
}
}