Array of N integers

n=int(input())
array=[int(input()) for i in range(n)]
table=[[-1]*(n+1) for i in range(n)]

for i in range(n):
    if i==0:
        if array[0]>=0:
            table[i][1]=array[0]
        else:
            table[i][1]=-1

    table[i][0]=0

for a in range(1,n):
    for b in range(1,i+2):
        table[a][b]=max(table[a][b],table[a-1][b]) if table[a-1][b]!=-1 else table[a][b]

        if table[a-1][b-1]>=0 and table[a-1][b-1]+array[a]>=0:
            table[a][b]=max(table[a][b],table[a-1][b-1]+array[a])

length=0

for a in range(n+1):
    if table[n-1][a]>=0:
        length=a

print(length)