#普通的DP 问题
if __name__ == "__main__":
    n = int(input())
    l = []
    for _ in range(n):
        l.append(int(input()))
    s = [0 for _ in range(n)]
    s[0] = l[0]
    ans = l[0]
    for i in range(1, n):
        if s[i-1]>0:
            s[i] = s[i-1] + l[i]
        else:
            s[i] = l[i]
        ans = max(ans, s[i])
    print(ans)