#include <iostream>
#include <assert.h>
#include <cstring>
#include <vector>
#include <queue>
#include <deque>
#include <algorithm>
using namespace std;

#define fo(x) freopen(#x ".in", "r", stdin), freopen(#x ".out", "w", stdout)
#define f1(i,k) for(int i=1,end_i=(k);i<=end_i;i++)
#define f0(i,k) for(int i=0,end_i=(k);i< end_i;i++)
#define cle(x) memset(x, 0, sizeof(x))
#define lobit(x) ((x) & -(x))
#define ll long long
#define pb push_back

const int inf = 2e18;
const int lim = 200005;
const int mv  = 1500;

int n,m;
int sn[lim], sm[lim];
int res;

int main(){
    cin>>n>>m;
    
    f1(i,n){ cin>>sn[i]; }
    f1(i,m){ cin>>sm[i]; }
    
    f1(i,n-1){
        res+=abs(sn[i]-sn[i+1]);
    }
    f1(i,m-1){
        res+=abs(sm[i]-sm[i+1]);
    }
    
    cout<<res<<endl;
    
    return 0;
}