c=0
d=list(map(int,input().split()))
n=d[0]
x=d[1]
y=d[2]
map_=[[0 for i in range(n+4)] for i in range(n+4)]
for i in range(x):
    l=list(map(int,input().split()))
    l1=l[0]+2
    l2=l[1]+2
    map_[l1-1][l2-1]=1;map_[l1-2][l2-1]=1;map_[l1-3][l2-1]=1;map_[l1][l2-1]=1;map_[l1+1][l1-1]=1
    map_[l1-1][l2-2]=1;map_[l1-2][l2-2]=1;map_[l1][l2-2]=1
    map_[l1-1][l2-3]=1
    map_[l1-1][l2]=1;map_[l1-2][l2]=1;map_[l1][l2]=1
    map_[l1-1][l2+1]=1
for i in range(y):
    m=list(map(int,input().split()))
    m1=m[0]+2
    m2=m[1]+2
    for j in range(0,5):
        for k in range(0,5):
            map_[m1-3+j][m2-3+k]=1
map__=[]
l=len(map_)
for i in range(0,l):
    p0=map_[i]
    pp=p0[2:-2]
    map__.append(pp)
map___=map__[2:-2]
for t in map___:
    for p in t:
        if p==0:
            c+=1
print(c)