#!/usr/bin/python3
import sys

code = []
with open("input") as fh:
    for ln in fh:
        code.append(int(ln))

def valid(code, o):
    for i in range(o - 25, o - 1):
        for j in range(i, o):
            if code[i] + code[j] == code[o]:
                return True

for o in range(25, len(code)):
    if not valid(code, o):
        target = code[o]
        break

for i in range(len(code)):
    for j in range(i + 1, len(code)):
        s = sum(code[i:j+1])
        if s == target:
            smallest = min(code[i:j+1])
            largest = max(code[i:j+1])
            print(smallest + largest)
            sys.exit(0)
        elif s > target:
            break # adding more numbers won't help