N = int(input())
L = [list(map(int,input().split())) for i in range(N)]
S = 0
for i in L:
for j in i:
S+=j
s = 0
e = 20000000
ans = 20000000000000
while s<=e:
mid = (s+e)//2
cnt = 0
for i in L:
for j in i:
cnt += min(j,mid)
if cnt >= (S+1)//2:
if ans > mid:
ans = mid
e = mid - 1
else:
s = mid + 1
print(ans)