from collections import defaultdict
N,M=map(int, input().split())
C=defaultdict(lambda: defaultdict(int))
for _ in range(N):
    b,c=map(int, input().split())
    C[c][b]+=1

res=0
for _,d in C.items():
    m=0
    s=0
    for k,v in d.items():
        m=max(v,m)
        s+=v
    res+=s-m
print(res)