#include <stdio.h>
#include <string.h>
#include <stdlib.h>
int main (void) {
char buf[128];
fgets(buf, 128, stdin);
char * c = buf;
int n = strtol(c, &c, 10);
c++;
int k = strtol(c, &c, 10);
int * zx = calloc(1000000, sizeof *zx);
int * zy = calloc(1000000, sizeof *zy);
int x = 0;
int y = 0;
int num = 0;
int vseh = 0;
while (1) {
char a = getchar();
switch (a) {
case EOF:
goto x;
case '\r':
break;
case '\n':
#ifndef EVAL
fprintf(stderr, "newline\n");
#endif
if (num) {
zx[num-1] = x;
zy[num-1] = y;
num = 0;
vseh++;
}
x = 0;
y++;
break;
case ' ':
#ifndef EVAL
fprintf(stderr, "presledek\n");
#endif
if (num) {
zx[num-1] = x;
zy[num-1] = y;
num = 0;
vseh++;
}
x++;
break;
default:
#ifndef EVAL
fprintf(stderr, "številka %c\n", a);
#endif
num *= 10;
num += a - '0';
}
}
x:;
long long int sum = 0;
int curx = 0;
int cury = 0;
for (int i = 0; i < vseh; i++) {
sum += abs(curx - zx[i]) + abs(cury - zy[i]);
#ifndef EVAL
fprintf(stderr, "znamenitost %d je na %d %d, sum je %lld\n", i, zx[i], zy[i], sum);
#endif
curx = zx[i];
cury = zy[i];
}
printf("%lld\n", sum);
}