```go
package main

import (
	"fmt"
	"sort"
)

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

	a := make([]int, 12)
	for i := 0; i < 12; i++ {
		fmt.Scan(&a[i])
	}

	sort.Sort(sort.Reverse(sort.IntSlice(a)))

	sum := 0
	months := 0
	for i := 0; i < 12; i++ {
		if sum >= k {
			break
		}
		sum += a[i]
		months++
	}

	if sum < k {
		fmt.Println(-1)
	} else {
		fmt.Println(months)
	}
}
```