
/*
TASK: BOOKS
LANG: C
*/

#include<stdio.h>

long long n,k,i,j,p,min;
long long a[201],pl[201];
long long b[201][201],c[201][201];

int main()
{
scanf("%lld %lld",&n,&k);
for (i=0;i<n;i++)
    scanf("%lld",&a[i]);
for (i=0;i<n;i++)
    scanf("%lld",&pl[i]);
for (i=0;i<n;i++)
    for (j=i;j<n;j++)
        b[i][j]=b[i][j-1]+a[j]*pl[j-i];
for (i=0;i<n;i++)
    c[0][i]=b[i][n-1];
for (i=1;i<k;i++)
    {
    for (j=0;j<n;j++)
        {
        min=c[i-1][j+1]+b[j][j];
        for (p=j+1;p<n;p++)
            if (min>c[i-1][p+1]+b[j][p])
               min=c[i-1][p+1]+b[j][p];
        c[i][j]=min;
        }
    }
printf("%lld\n",c[k-1][0]);
return 0;
}
