#define _CRT_SECURE_NO_WARNINGS
#include <stdlib.h>
#include <stdio.h>

int off() {
	int T, myBreaks, HanoBreaks;
	scanf("%d", &T);
	scanf("%d", &myBreaks);
	int** AB = (int**)malloc(sizeof(int*) * myBreaks);
	for (int i = 0; i < myBreaks; i++)
	{
		AB[i] = (int*)malloc(sizeof(int) * 2);
		scanf("%d%d", &AB[i][0], &AB[i][1]);
	}
	scanf("%d", &HanoBreaks);
	int** XY = (int**)malloc(sizeof(int*) * HanoBreaks);
	for (int i = 0; i < HanoBreaks; i++)
	{
		XY[i] = (int*)malloc(sizeof(int) * 2);
		scanf("%d%d", &XY[i][0], &XY[i][1]);
	}

	
	int* start = (int*)malloc(sizeof(int) * (myBreaks + HanoBreaks));
	int* end = (int*)malloc(sizeof(int) * (myBreaks + HanoBreaks));
	int a = 0, b = 0, c = 0;
	for (int i = 0; i < myBreaks + HanoBreaks; i++)
	{
		if (a >= myBreaks)
		{
			start[c] = XY[b][0];
			c++;
			b++;
			continue;
		}
		if (b >= HanoBreaks)
		{
			start[c] = AB[a][0];
			c++;
			a++;
			continue;
		}
		if (AB[a][0] <= XY[b][0])
		{
			start[c] = AB[a][0];
			c++;
			a++;
			continue;
		}
		start[c] = XY[b][0];
		c++;
		b++;
	}
	a = 0; b = 0; c = 0;
	for (int i = 0; i < myBreaks + HanoBreaks; i++)
	{
		if (a >= myBreaks)
		{
			end[c] = XY[b][1];
			c++;
			b++;
			continue;
		}
		if (b >= HanoBreaks)
		{
			end[c] = AB[a][1];
			c++;
			a++;
			continue;
		}
		if (AB[a][1] <= XY[b][1])
		{
			end[c] = AB[a][1];
			c++;
			a++;
			continue;
		}
		end[c] = XY[b][1];
		c++;
		b++;
	}


	int s = 0, e = 0;
	int kozos = 0;
	for (int i = 0; i < (myBreaks + HanoBreaks) * 2; i++)
	{
		if (start[s] <= end[e])
		{
			s++;
		}
		else
		{
			e++;
			int interval = end[e - 1] - start[s - 1] + 1;
			if (interval > 0)
			{
				kozos += interval;
			}
		}
		
	}

	printf("%d", kozos);





	for (int i = 0; i < myBreaks; i++)
	{
		free(AB[i]);
	}
	for (int i = 0; i < HanoBreaks; i++)
	{
		free(XY[i]);
	}
	free(AB);
	free(XY);
	free(start);
	free(end);
	return 0;
}

int main() {
	int T, myBreaks, HanoBreaks;
	scanf("%d", &T);
	scanf("%d", &myBreaks);
	int* AB = (int*)malloc(sizeof(int) * myBreaks * 2);
	for (int i = 0; i < myBreaks * 2; i += 2)
	{
		scanf("%d%d", &AB[i], &AB[i + 1]);
	}
	scanf("%d", &HanoBreaks);
	int* XY = (int*)malloc(sizeof(int) * HanoBreaks * 2);
	for (int i = 0; i < HanoBreaks * 2; i += 2)
	{
		scanf("%d%d", &XY[i], &XY[i + 1]);
	}


	int a = 0, b = 0, kozos = 0;
	while (a < myBreaks * 2 && b < HanoBreaks * 2)
	{
		if (XY[b] - AB[a] > T)
		{
			a += 2;
			continue;
		}
		if (AB[a] <= XY[b] && AB[a + 1] >= XY[b])
		{
			if (XY[b + 1] < AB[a + 1])
			{
				kozos += XY[b + 1] - XY[b] + 1;
				b += 2;
				continue;
			}
			kozos += AB[a + 1] - XY[b] + 1;
		}
		if (AB[a] <= XY[b + 1])
		{
			if (AB[a + 1] < XY[b + 1])
			{
				kozos += AB[a + 1] - AB[a] + 1;
				a += 2;
				continue;
			}
			kozos += XY[b + 1] - AB[a] + 1;
		}
		a += 2;
	}

	printf("%d", kozos);
	free(AB);
	free(XY);
	return 0;
}