#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define ll long long
#define ld long double
using namespace std;
using namespace __gnu_pbds;
typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;
const int NMAX = 2e5;
const ll INF = 1e18;
struct AIB {
int n;
int log_n;
ll aib[2 * NMAX + 1];
void Initialize(int n) {
this->n = n;
log_n = 0;
while((1 << (log_n + 1)) <= n) {
log_n++;
}
for(int i = 1; i <= n; i++) {
aib[i] = 0;
}
}
void Update(int pos, ll value) {
for(int i = pos; i <= n; i += i & (-i)) {
aib[i] += value;
}
}
ll Query(int pos) {
ll answer = 0;
for(int i = pos; i >= 1; i -= i & (-i)) {
answer += aib[i];
}
return answer;
}
int GetValue(int k) {
int pos = 0;
int sum = 0;
for(int i = log_n; i >= 0; i--) {
if(pos + (1 << i) <= n && sum + aib[pos + (1 << i)] < k) {
sum += aib[pos + (1 << i)];
pos += (1 << i);
}
}
return pos + 1;
}
}aib_freq, aib_sum;
int k, n, ind, ID;
ll answer;
pair<int, int> houses[NMAX + 1];
int a[2 * NMAX + 1];
ll min_left[NMAX + 1];
ll min_right[NMAX + 2];
int values[2 * NMAX + 1];
map<int, int> mp;
void Update(int x, int y) {
aib_freq.Update(mp[x], 1);
aib_freq.Update(mp[y], 1);
aib_sum.Update(mp[x], x);
aib_sum.Update(mp[y], y);
}
ll GetMinDistance(int n) {
int median = aib_freq.GetValue(n / 2 + 1);
int real_median = values[median];
int smaller_equal = aib_freq.Query(median);
int greater = n - smaller_equal;
ll sum_smaller_equal = aib_sum.Query(median);
ll sum_greater = aib_sum.Query(ID) - sum_smaller_equal;
ll min_distance = (ll) real_median * smaller_equal - sum_smaller_equal + sum_greater - (ll) real_median * greater;
return min_distance;
}
void Solve1() {
for(int i = 1; i <= n; i++) {
a[++ind] = houses[i].first;
a[++ind] = houses[i].second;
}
sort(a + 1, a + ind + 1);
for(int i = 1; i <= ind; i++) {
answer += abs(a[i] - a[ind / 2 + 1]);
}
// cout << answer << '\n';
answer += n;
cout << answer << '\n';
}
void Solve2() {
for(int i = 1; i <= n; i++) {
mp[houses[i].first] = 1;
mp[houses[i].second] = 1;
}
for(auto &x : mp) {
x.second = ++ID;
values[ID] = x.first;
}
aib_sum.Initialize(ID);
aib_freq.Initialize(ID);
for(int i = 1; i <= n; i++) {
Update(houses[i].first, houses[i].second);
min_left[i] = GetMinDistance(2 * i);
}
aib_sum.Initialize(ID);
aib_freq.Initialize(ID);
min_right[n + 1] = INF;
for(int i = n; i >= 1; i--) {
Update(houses[i].first, houses[i].second);
min_right[i] = GetMinDistance(2 * (n - i + 1));
}
// for(int i = 1; i <= n; i++) {
// cout << min_left[i] << ' ';
// }
// cout << '\n';
ll answer_bridge = INF;
for(int i = 1; i < n; i++) {
answer_bridge = min(answer_bridge, min_left[i] + min_right[i + 1]);
}
answer += answer_bridge;
answer += n;
cout << answer << '\n';
}
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin >> k >> n;
for(int i = 1; i <= n; i++) {
char z1, z2;
int x, y;
cin >> z1 >> x >> z2 >> y;
if(z1 != z2) {
houses[++ind] = {x, y};
}
else {
answer += abs(x - y);
}
}
n = ind;
ind = 0;
if(k == 1) {
Solve1();
}
else {
Solve2();
}
return 0;
}
