//UVA10003 Cutting Sticks
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
const int MAXN = 50 + 5;
int len, n;
int a[MAXN], vis[MAXN][MAXN];
int d[MAXN][MAXN];
int dp(int i, int j) {
if(j - i <= 1) return 0;
if(vis[i][j]) return d[i][j];
vis[i][j] = 1;
int& ans = d[i][j];
ans = -1;
for(int k = i + 1; k <= j - 1; k++) {
int v = dp(i, k) + dp(k, j) + a[j] - a[i];
if(ans == -1 || v < ans) ans = v;
}
return ans;
}
int main() {
while(scanf("%d", &len) == 1 && len) {
scanf("%d", &n);
memset(vis, 0, sizeof(vis));
a[0] = 0; a[n + 1] = len;
for(int i = 1; i <= n; i++) scanf("%d", &a[i]);
printf("The minimum cutting is %d.\n", dp(0, n + 1));
}
return 0;
}
/*
100
3
25 50 75
10
4
4 5 7 8
0
*/
