#include <cstdio>

#include <cstring>

#include <iostream>

#include <algorithm>

#define N 100001

#define max(x, y) ((x) > (y) ? (x) : (y))

#define min(x, y) ((x) < (y) ? (x) : (y))

int t, s, n, ans, mx = 1;

int val[N], f[N][101];

//val[i]表示滑雪能力为i时一次滑雪的最低耗时

//f[i][j]表示时间为i，滑雪能力为j所能滑的最多次数 

struct ovo

{

	int m, l, a;

}q[N];

struct qwq

{

	int c, d;

}p[N];

inline int read()

{

	int x = 0, f = 1;

	char ch = getchar();

	for(; !isdigit(ch); ch = getchar()) if(ch == '-') f = -1;

	for(; isdigit(ch); ch = getchar()) x = (x << 1) + (x << 3) + ch - '0';

	return x * f;

}

inline bool cmp(qwq x, qwq y)

{

	return x.c < y.c;

}

int main()

{

	int i, j;

	t = read();

	s = read();

	n = read();

	for(i = 1; i <= s; i++)

	{

		q[i].m = read();

		q[i].l = read();

		q[i].a = read();

	}

	for(i = 1; i <= n; i++)

	{

		p[i].c = read();

		p[i].d = read();

	}

	std::sort(p + 1, p + n + 1, cmp);

	j = 1;

	val[0] = 1e9;

	for(i = 1; i <= 100; i++)

	{

		val[i] = val[i - 1];

		for(; i == p[j].c && j <= n; j++) val[i] = min(val[i], p[j].d);

	}

	memset(f, -1, sizeof(f));

	f[0][1] = 0;

	for(i = 0; i <= t; i++)

	{

		mx = -1;

		for(j = 1; j <= 100; j++)

		{

			f[i + 1][j] = max(f[i + 1][j], f[i][j]);

			if(f[i][j] != -1 && val[j] != 1e9)

			{

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

				f[i + val[j]][j] = max(f[i + val[j]][j], f[i][j] + 1);

			}

		}

		for(j = 1; j <= s; j++)

			if(mx != -1 && i >= q[j].m)

				f[i + q[j].l][q[j].a] = max(f[i + q[j].l][q[j].a], mx);

	}

	for(i = 1; i <= 100; i++) ans = max(ans, f[t][i]);

	printf("%d\n", ans);

	return 0;

}