#include<iostream>
#include<cstdio>
#include<cstdlib>
using namespace std;
int t,s,n,q[10001][101]={0},ji=1;
int s1[101][3],used[100]={0};
int n1[10000][2],answer=0;
int main()
{
	freopen ("ski.in","r",stdin);
	freopen ("ski.out","w",stdout);
	cin>>t>>s>>n;
	for (int i=1;i<=s;i++)
	{
		int a,b,c;
		cin>>a>>b>>c;
		s1[i][0]=a;
		s1[i][1]=a+b;
		s1[i][2]=c;
	}
	used[1]=1;
	for (int i=1;i<=n;i++)
	{
		cin>>n1[i][0]>>n1[i][1];
	}
	int i=1;
	for (i=1;i<=t;i++)
	{
		for (int j=1;j<=ji;j++)
		{
			for (int k=1;k<=n;k++)
			{
				if (n1[k][0]<=j&&i-n1[k][1]>=0)
				{
					q[i][j]=max(q[i][j],q[i-n1[k][1]][j]+1);
				}
			}
			for (int k=1;k<=s;k++)
			{
				if (s1[k][1]==i)
				{
					q[i][s1[k][2]]=max(q[i][s1[k][2]],q[s1[k][0]][j]);
					if (s1[k][2]>ji)
						ji=s1[k][2];
				}
			}
			if (q[i][j]>answer)
				answer=q[i][j];
		}
	}
	cout<<answer;
	return 0;
}