d, n, m = map(int, raw_input().split())
missing = {int(day): set([]) for day in raw_input().split()}

covered = 0

while m:
    start, end = map(int, raw_input().split())
    days = frozenset({start, end})

    for day in missing:
        if day >= start and day <= end:
            missing[day].add(days)

    m -= 1

intersections = []
solved = []

for day, intervals in missing.iteritems():
    for day1, intervals1 in missing.iteritems():
        if day == day1:
            continue

        result = intervals & intervals1

        if result and result not in intersections:
            intersections.append(result)

        if result:
            solved.append(day)
            solved.append(day1)

l = 0
for day in missing:
    if day not in solved:
        l += 1

print l + len(intersections)