#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vll = vector<ll>;
using vvl = vector<vll>;
using pll = pair<ll,ll>;
using vpl = vector<pll>;
using vvp = vector<vpl>;
#define f first
#define s second
#define pb push_back
#define all(v) v.begin(),v.end()
vpl ord;ll n;
vll rs;
ll ran(ll l, ll r, ll m){
if(r-m>m-l){
return -ord[m-1].f*(r-m-m+l);
}
else{
return ord[m].f*(m-l-r+m);
}
}
long long min_total_length(std::vector<int> r, std::vector<int> b) {
ord.clear();
for(ll i: r)ord.pb({i,1});
for(ll i: b)ord.pb({i,0});
sort(all(ord));
n = ord.size();
rs = vll(n+1);
vll st={0};
for(ll i = 0; i < n; ++i){
rs[i+1]=rs[i]+ord[i].f;
if(i+1<n && ord[i+1].s!=ord[i].s){st.pb(i+1);}
}
st.pb(n);
reverse(all(st));
vll dp(n+1, 1e17);
vll dp1(n+1, 1e17);
ll las=0, bf=0;
dp[0]=0;
dp1[0]=-rs[st.back()];
for(ll p = 0; p < st.size(); ++p){
bf=las;las=st.back();st.pop_back();
for(ll i = las; i < st.back(); ++i){
for(ll j = bf+1; j < las && j<2*las+i; ++j){
dp[i+1] = min(dp[i+1], dp1[j]+ran(j,i+1, las));
}
}
for(ll i = st.back()-1; i >= las; --i){
for(ll j = max(bf+1,2*las+i); j < las; ++j){
dp[i+1] = min(dp[i+1], dp1[j]+ran(j,i+1, las));
}
dp[i+1]+=rs[i+1]-rs[las];
if(bf!=las)dp[i+1]=min(dp[i+1], dp[bf]+ran(bf,i+1,las)+rs[i+1]-rs[las]-rs[las]+rs[bf]);
if(bf+1==las)dp[i+1]=min(dp[i+1], dp[bf+1]+ran(bf,i+1,las)+rs[i+1]-rs[las]-rs[las]+rs[bf]);
dp1[i+1]=dp[i+1];
dp1[i+1]+=-rs[st.back()]+rs[i+1];
}
}
return dp[n];
}
int main() {
int n, m;
assert(2 == scanf("%d %d", &n, &m));
vector<int> r(n), b(m);
for(int i = 0; i < n; i++)
assert(1 == scanf("%d", &r[i]));
for(int i = 0; i < m; i++)
assert(1 == scanf("%d", &b[i]));
long long res = min_total_length(r, b);
printf("%lld\n", res);
return 0;
}
