from sys import stdin, stdout

def main():
    
    global hanop
    hanop = int(0)
    t = int(stdin.readline())
    n = int(stdin.readline())
    te_szuneted=[]
    hano_szunete=[]
    for i in range(0,n):
        te_szuneted.append(stdin.readline().split())
    m = int(stdin.readline())
    for j in range(m):
        hano_szunete.append(stdin.readline().split())
    #print(te_szuneted)
    #print(hano_szunete)
    opercek:int = 0
    tszam:int = 0
    te_szuneted = [[int(j) for j in i] for i in te_szuneted]
    hano_szunete = [[int(j) for j in i] for i in hano_szunete]
    #print(te_szuneted)
    #print(hano_szunete)
    def online(ido:int, hano_szunete_p:list[list[int]]) -> bool:
        global hanop
        try:
            while hano_szunete_p[hanop][1] < ido:
                hanop+=1
                if hanop>=len(hano_szunete_p):
                    return False
        except Exception:return False
        
        if hano_szunete_p[hanop][0] <= ido:
            return True
        else:
            #print(f"false, ido: {ido} ")
            return False
    for i in te_szuneted:
        for j in range(i[0],i[1]+1):
            #print("ido: "+str(j))
            tszam+=1
            if online(j,hano_szunete):
                tszam = 0
                #print(f"i: {i} j: {j}")
                opercek+=1
            if tszam==t:
                break
        tszam=0
    stdout.write(str(int(opercek)))
    return 0
main()