#include<bits/stdc++.h>
using namespace std;
#define lalala ios_base::sync_with_stdio(false);cin.tie(NULL);
//#define endl "\n"
#define ll long long
#define pb push_back
#define N 200005
// süre nerde pokemon_deg
vector<tuple<ll int,ll int,ll int>> pokemon;
int n,m,k;
ll int dp[102][103][2002];
map<int,int> mp;
ll int hesap(int hangi_pokemon,ll int sn,ll int sonyer){
if(dp[hangi_pokemon][sonyer][sn]!=-1)return dp[hangi_pokemon][sonyer][sn];
if(hangi_pokemon>=m)return 0;
ll int a=hesap(hangi_pokemon+1,sn,sonyer);
ll int b=0;
ll int nerde,deg,tim;
tie(tim,nerde,deg)=pokemon[hangi_pokemon];
ll int xxx,yyy,zzz;
if(sonyer!=102)tie(yyy,xxx,zzz)=pokemon[sonyer];
else xxx=k;
if(tim>abs(nerde-xxx)+sn){
b=hesap(hangi_pokemon+1,sn+abs(nerde-xxx),hangi_pokemon)+deg;
}
dp[hangi_pokemon][sonyer][sn]=max(a,b);
return dp[hangi_pokemon][sonyer][sn];
}
int main(){
lalala;
memset(dp,-1,sizeof(dp));
int mm;cin>>n>>k>>mm;
ll int cev=0;
for(int i=0;i<mm;i++){
ll int a,b,c;cin>>a>>b>>c;
if(a==k){
cev+=b;
continue;
}
if(abs(k-a)<c){
m++;
pokemon.pb({c,a,b});
}
}
sort(pokemon.begin(),pokemon.end());
cout<<hesap(0,0,102)+cev<<endl;
}
