import sys
input = sys.stdin.readline

def main():
    N = int(input())
    tmp = list(map(int, input().split()))
    if len(tmp) > 1:
        print("\"assert\"")
    else:
        a = [tmp[0]]
        for i in range(N-1):
            a.append(int(input()))
        a = sorted(a, reverse=True)
        if a[0] == a[1]:
            print(a[1]+a[2])
        else:
            if a[1] == a[2]:
                print(a[1]+a[2])
            else:
                print(a[0]+a[2])

if __name__ == "__main__":
    main()