def merge(left,right):
    sl=[]
    l=0
    r=0
    while l<len(left) and r<len(right):
        if left[l][0]<=right[r][0] or (left[l][0]==right[r][0] and left[l][1]<=right[r][1]):
            sl.append(left[l])
            l+=1
        else:
            sl.append(right[r])
            r+=1
    if len(left)!=l:
        sl.extend(left[l:])
    if len(right)!=r:
        sl.extend(right[r:])
    return sl

def msort(L):
    if len(L)<=1:
        return L
    mid=len(L)//2
    left=msort(L[:mid])
    right=msort(L[mid:])
    return list(merge(left,right))


n=int(input())
ab=[]
for i in range(n):
    ab.append(tuple(map(int,input().split())))

lis=msort(ab)
ul=[0]
li=[0 for i in range(n)]
li[0]=1
for i in range(0,n):
    u=len(ul)
    d=0
    while u-d>1:
        mid=(u+d)//2
        if ul[mid]<=lis[i][0]:
            d=mid
        else:
            u=mid
    if d+1==len(ul):
        ul.append(lis[i][1])
    li[i]=d+1
    ul[d+1]=min(ul[d+1],lis[i][1])
    #print(ul)
    #print(li)
print(n-max(li))