const maxn=;

 var t,s,n,i,j,m,l,a,c,d:longint;

 f,e:array[..,..maxn] of longint;

 q:array[..] of longint;

 g:array[..maxn] of longint;

 function max(a,b:longint):longint;

 begin

   if a>b then exit(a)

     else exit(b);

 end;

 begin

   readln(t,s,n);

   for i:= to s do

     begin

       readln(m,l,a);

       e[a,l+m]:=max(e[a,l+m],m);

     end;

   for i:= to  do q[i]:=maxn;

   for i:= to n do

     begin

       readln(c,d);

       for j:=c to  do

         q[j]:=d+q[j]-max(d,q[j]);

     end;

   //for i:=1 to 100 do

     //writeln(q[i]);

   for i:= to t do

     for j:= to  do f[j,i]:=-maxn;

   f[,]:=; //g[1]:=0;

   for i:= to t do

     for j:= to  do

       begin

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

         if e[j,i]> then f[j,i]:=max(f[j,i],g[e[j,i]]);

         if q[j]<=i then f[j,i]:=max(f[j,i],f[j,i-q[j]]+);

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

       end;

   writeln(g[t]);

 end.