For problem statement at 0-999/300-399/300-309/309/problemA.txt this is a correct solution, but verifier at 0-999/300-399/300-309/309/verifierA.go ends with exit status 2 can you fix the verifier? ```go
func checkDistances(s string, distance []int) bool {
    firstIndex := make([]int, 26)
    for i := range firstIndex {
        firstIndex[i] = -1
    }
    for i, c := range s {
        idx := int(c - 'a')
        if firstIndex[idx] != -1 {
            if i - firstIndex[idx] - 1 != distance[idx] {
                return false
            }
        } else {
            firstIndex[idx] = i
        }
    }
    return true
}
```