N=int(input())
try:
  A=[int(input()) for _ in range(N)]
  a=A[0]+A[1]
  b=A[0]+A[2]
  c=A[1]+A[2]
  AA=sorted([a,b,c])
  if b!=c:
    print(AA[1])
  else:
    print(AA[0])
except:
  print("assert")