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