package no247; import java.util.Arrays; import java.util.Scanner; public class Main { public static final int INF = 1 << 29; public static void main(String[] args) { Scanner sc = new Scanner(System.in); int c = sc.nextInt(); int n = sc.nextInt(); int[] a = new int[n]; for(int i=0;i<n;i++) { a[i] = sc.nextInt(); } int[][] dp = new int[n+1][c+1]; for(int i=0;i<=n;i++) { Arrays.fill(dp[i], INF); } for(int i=0;i<=n;i++) { dp[i][0] = 0; } for(int i=1;i<=n;i++) { for(int j=0;j<=c;j++) { dp[i][j] = dp[i-1][j]; if (j >= a[i-1]) { dp[i][j] = Math.min(dp[i][j], dp[i][j-a[i-1]] + 1); } } } System.out.println(dp[n][c] == INF ? -1 : dp[n][c]); } }