C++ :

#include<cstdio>
#include<cstring>
#include<string>
#include<algorithm>
using namespace std;
int f[10010];
int word[10010];
int n,num;
int main()
{
    scanf("%d\n",&n);
    num=0;
    char s[101];
    while (scanf("%s",s)!=EOF)
    word[++num]=strlen(s);
    memset(f,255,sizeof(f));
    f[0]=0;
    for (int i=0;i<num;i++){
        int len=0;
        for (int j=1;1;j++){
            if (i+j>num) break;
            int bad=0;
            len=len+word[i+j];
            if (len+j-1>n) break;
            if (j==1&&len<n) bad=500;
            else if (j==1) bad=0;
            else
            {
                int k,kk;
                k=(n-len)/(j-1);
                kk=(n-len)-k*(j-1);
                bad=kk*k*k+(k-1)*(k-1)*(j-kk-1);
            }
            if ((f[i]+bad<f[i+j])||(f[i+j]==-1)) f[i+j]=f[i]+bad;
        }
    }
    printf("Minimal badness is %d.\n",f[num]);
    return 0;
}