N = int(input())

try:
    A1 = int(input())
    A2 = int(input())
    A3 = int(input())
except:
    print("\"assert\"")
    exit()
    
ans = []
ans.append(A1+A2)
ans.append(A2+A3)
ans.append(A1+A3)
ans = sorted(ans)

if ans[1] == ans[2]:
    print(ans[0])
else:
    print(ans[1])