N=int(input())

friendlist=[0 for i in range(N+2)]


for i in range(N):
    a,b=[int(j) for j in input().split(" ")]
    for k in range(a,min(b+1,N+2)):
        friendlist[k]+=1


#ab=[[int(i) for i in input().split(" ")] for j in range(N)]

#print(ab)

k=N+1
i=0
while k>=0:
    if friendlist[k]>=k-1:
        i=k-1
        break
    k-=1

print(i)
    
        