There are is no solution for the following input:
4
0011
The sum of positions of 1's in this word is 7. If we change
any one of 1's to 0, we won't get multiple of 5(=4+1).

1) The source word  HAS the property "the sum of positions
where symbols 1 are located is a multiple of (N+1) or equal
to zero.
"

2) your are given the word that ALWAYS have it's source

3) So your input is impossible.