```go
package main

import "fmt"

func main() {
	var n int
	fmt.Scan(&n)

	adj := make([]string, n)
	for i := 0; i < n; i++ {
		fmt.Scan(&adj[i])
	}

	target := n - 1
	visited := make([]bool, n)
	queue := []int{0}
	visited[0] = true

	copies := 0

	for len(queue) > 0 {
		u := queue[0]
		queue = queue[1:]

		if adj[u][target] == '1' {
			copies++
		}

		for v := 0; v < n; v++ {
			if v != target && adj[u][v] == '1' && !visited[v] {
				visited[v] = true
				queue = append(queue, v)
			}
		}
	}

	fmt.Println(copies)
}
```