from collections import deque 
q = deque() 
n = int(input()) 
a = [] 
for i in range(n): 
    row = input().split() 
    for i in range(len(row)): 
        row[i] = int(row[i]) 
    a.append(row) 
v = [-1]*n 
str = input().split() 
s = int(str[0]) - 1 
f = int(str[1]) - 1 
v[s] = 0 
q.append(s) 
while len(q) > 0: 
    u = q.popleft() 
    for i in range (n): 
        if a[i][u] == 1 and v[i] == -1: 
            v[i] = v[u] + 1 
            q.append(i) 
print(v[f]) 
if v[f] > 0: 
    x = [0]*(v[f] + 1) 
    x[0] = f 
    for i in range(1, v[f] + 1): 
        for j in range(n): 
            if (a[j][x[i - 1]] == 1 and v[j] == v[x[i-1]] - 1): 
                x[i] = j 
                break 
y = [0]*len(x)
for i in range(len(x)):
    y[i] = x[len(x) - 1 - i]
    print(y[i] + 1, end=' ')
 

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

NQowIDEgMCAwIDEKMSAwIDEgMCAwCjAgMSAwIDAgMAowIDAgMCAwIDAKMSAwIDAgMCAwCjMgNQ==

5
0 1 0 0 1
1 0 1 0 0
0 1 0 0 0
0 0 0 0 0
1 0 0 0 0
3 5