Untitled

from collections import defaultdict 
n = int(input()) 
arr = [] 
for i in range(n):
    arr.append(int(input())) 
print(arr) 
hashmap = defaultdict(int) 
maxlen = 0  
psum = 0
for i in range(len(arr)): 
    psum += arr[i] 
    if psum == 0:
        maxlen = i + 1 
    elif psum in hashmap:
        maxlen = max(maxlen,i - hashmap[psum]) 
    else:
        hashmap[psum] = i 
print(maxlen)