file = open('input.txt','r')

tmp = file.readlines()
data = []

for f in tmp:
    data.append(int(f.replace('\n','')))


def validNumbers(num):
    num -= 1
    res = []
    rng = range(num - 26, num )
    for x in rng:
        for y in rng:
            if data[x] == data[y]:
                continue
            res.append(data[x]+data[y])
    return res


def sumInRange(rng):
    sum = 0
    for i in rng:
        sum += data[i]
    return sum

def findWeakness(rng):
    smal = 99999999999
    high = 0
    for i in rng:
        if data[i] < smal:
            smal = data[i]
        if data[i] > high:
            high = data[i]
    print(smal+high)

for i in range(1,len(data)):
    end = i
    while end < len(data):
        rng = range(end - i,end)
        if sumInRange(rng) == 248131121:
            findWeakness(rng)            
        end += 1

exit()

count = 0
preamble = []
for d in data:
    count += 1
    if count <= 25:
        continue
    val =  validNumbers(count)
    if data[count - 1] not in val:
        print('count: '+str(count))
        print('preamble: ')
        for i in range(count - 27,count - 2):
            preamble.append(data[i])
        print(preamble)
        print('valid:')
        print(val)
        print('odd one is: '+str(data[count - 1]))
        exit()