i[1] is 3 which is out of range [1,nrow=2] code example
Example: for i in range(n-1,0,-1):
# Print first 5 numbers using range function
for i in range(5):
print(i, end=', ')
# Output:
# 0, 1, 2, 3, 4,
# Print first 5 numbers using range function
for i in range(5):
print(i, end=', ')
# Output:
# 0, 1, 2, 3, 4,