// Not afraid to dark.

#include <bits/stdc++.h>
using namespace std;

clock_t start_time, end_time;
#define GET_START start_time = clock ();
#define GET_END end_time = clock (); fprintf (stderr, "TIME COSSEMED : %0.3lf\n", 1.0 * (end_time - start_time) / CLOCKS_PER_SEC);
#define inline __inline__ __attribute__ ((always_inline))

namespace io {
    int read_pos, read_dt; char read_char;
    inline int read (int &p = read_pos){
        p = 0, read_dt = 1; read_char = getchar ();
        while (! isdigit (read_char)){
            if (read_char == '-')
                read_dt = - 1;
            read_char = getchar ();
        }
        while (isdigit (read_char)){
            p = (p << 1) + (p << 3) + read_char - 48;
            read_char = getchar ();
        }
        return p = p * read_dt;
    }
    int write_sta[65], write_top;
    inline void write (int x){
        if (x < 0)
            putchar ('-'), x = - x;
        write_top = 0;
        do
            write_sta[write_top ++] = x % 10, x /= 10;
        while (x);
        while (write_top)
            putchar (write_sta[-- write_top] + 48);
    }
}

signed main (){
    GET_START

    int n, m;
    long long ans = 0;
    io::read (n), io::read (m);
    for (int i = 1, ls, u = 0;i <= n;++ i){
        ls = u;
        io::read (u);
        if (ls)
            ans += abs (ls - u);
    }
    for (int i = 1, ls, u = 0;i <= m;++ i){
        ls = u;
        io::read (u);
        if (ls)
            ans += abs (ls - u);
    }
    io::write (ans), puts ("");

    GET_END
    return 0;
}