I

s1, q, s, n =[], [], [], int(input())
for i in range(n):
    s.append([])
    s[i].append(tuple(map(int, input().split())))
    s1.extend(s[i])
s1.sort()
for i in range(len(s1)):
    for j in range(len(s1)):
        if i != j and s1[i][0] == s1[j][0] and (s1[i][0] not in q or s1[j][0] not in q):
            if s1[i][1] > s1[j][1]:
                q.append(s1[i])
                q.append(s1[j])
            else:
                q.append(s1[j])
                q.append(s1[i])
print(q)