numberOf = int(input())
arr = input().split()
resultedArr = []
for i in range(0, numberOf):
    counter = int(arr[i])
    for j in range(i, numberOf):
        if(counter < int(arr[j])):
             counter += int(arr[j])
    resultedArr.append(counter)
maximum = resultedArr[0]
for i in range(1, len(resultedArr)):
    if(maximum < resultedArr[i]):
        maximum = resultedArr[i]
print(maximum)