-1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -

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"""
6
0 2 4 -1 -1 -1
2 0 9 7 -1 -1
4 9 0 8 1 -1
-1 7 8 0 3 1
-1 -1 1 3 0 2
-1 -1 -1 1 2 0
6 1 6
0 2 1 -1 -1 -1
2 0 9 7 -1 -1
1 9 0 8 4 -1
-1 7 8 0 3 1
-1 -1 4 3 0 5
-1 -1 -1 1 5 0
"""
INF = 10000001
N,A,B = map(int, input().split())
W = []
for i in range(N):
row = list(map(int, input().split()))
W.append(row)
for i in range(N):
for j in range(N):
if W[i][j] < 0: W[i][j] = INF
'''
print ( "Весовая матрица графа: " )
for i in range(N):
for j in range(N):
if W[i][j] == INF: print ( " *", end="" )
else: print ( "%4d" %W[i][j], end="" )
print();
'''
'''
P = []
for i in range(N):
P.append([i]*N)
P[i][A-1] = 0
print(P)
'''
for k in range(N):
for i in range(N):
for j in range(N):
if W[i][k] + W[k][j] < W[i][j]:
W[i][j] = W[i][k] + W[k][j]
#P[i][j] = P[k][j]
if W[A-1][B-1]==INF or N==0:
print(-1)
else:
print(W[A-1][B-1])
'''
print ("\nМатрица кратчайших расстояний:");
for i in range(N):
for j in range(N): print ( "%4d" %(W[i][j]), end="" )
print();
'''
'''
print ( "\nВспомогательная матрица:");
for i in range(N):
for j in range(N):
print( "%4d" %P[i][j], end="" )
print()
print()
for i in range(N):
print ("Кратчайшие маршруты из вершины:", i+1)
for k in range(N):
if k != i:
j = k
while j != -1:
print ( "%2d" %(j+1), end="" )
if j != i:
print ( " <= ", end="" );
j = P[i][j];
print();
'''