#include <cstring>

 #include <cstdio>

 #define min(a,b) (a<b?a:b)

 #define max(a,b) (a>b?a:b)

 inline void read(int &x)

 {

     x=; register char ch=getchar();

     for(; ch>''||ch<''; ) ch=getchar();

     for(; ch>=''&&ch<=''; ch=getchar()) x=x*+ch-'';

 }

 const int N();

 const int M();

 int n,s,t,tim[M];

 int able[N<<][M],f[N][M];

 int Presist()

 {

     read(t),read(s),read(n);

     for(int u,v,w,i=; i<=s; ++i)

     {

         read(u),read(v),read(w),v+=u;

         able[v][w]=max(able[v][w],u);

     }

     memset(tim,/,sizeof(tim));

     for(int lim,cost,i=; i<=n; ++i)

     {

         read(lim),read(cost);

         for(; lim<=; ++lim)

             tim[lim]=min(tim[lim],cost);

     }

     memset(f,-,sizeof(f));f[][]=;

     for(int i=; i<N; ++i) f[i][]=;

     for(int i=; i<=t; ++i)

         for(int j=; j<=; ++j)

         {

             f[i][j]=f[i-][j];

             if(able[i][j]) f[i][j]=max(f[i][j],f[able[i][j]][]);

             if(i-tim[j]>=) f[i][j]=max(f[i][j],f[i-tim[j]][j]+);

             f[i][]=max(f[i][],f[i][j]);

         }

     printf("%d\n",f[t][]);

     return ;

 }

 int Aptal=Presist();

 int main(int argc,char**argv){;}