#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
using pil = pair<int, ll>;
#define pb push_back
#define ff first
#define ss second
const ll inf = numeric_limits<ll> :: max();
struct DS{
vector<pil> t;
vector<int> imp;
int n, cc;
void init(vector<int> imps){
sort(imps.begin(), imps.end());
for (int i = 0; i < imps.size(); i++){
if (!i || imps[i - 1] != imps[i]){
imp.pb(imps[i]);
}
}
n = (int) imp.size();
t.resize(4 * n);
cc = 0;
}
void upd(int v, int tl, int tr, int& p, int& x){
if (tl == tr){
t[v].ff++;
t[v].ss += x;
return;
}
int tm = (tl + tr) / 2, vv = 2 * v;
if (p <= tm){
upd(vv, tl, tm, p, x);
}
else {
upd(vv + 1, tm + 1, tr, p, x);
}
t[v].ff = t[vv].ff + t[vv + 1].ff;
t[v].ss = t[vv].ss + t[vv + 1].ss;
}
void upd(int p, int x){
upd(1, 1, n, p, x);
}
pil get(int v, int tl, int tr, int& l, int& r){
if (l > tr || r < tl) return {0, 0};
if (l <= tl && tr <= r){
return t[v];
}
int tm = (tl + tr) / 2, vv = 2 * v;
pil p1 = get(vv, tl, tm, l, r), p2 = get(vv + 1, tm + 1, tr, l, r);
return {p1.ff + p2.ff, p1.ss + p2.ss};
}
pair<int, ll> get(int l, int r){
return get(1, 1, n, l, r);
}
priority_queue<int> s1;
priority_queue<int, vector<int>, greater<int>> s2;
vector<int> :: iterator it;
void add(int x){
cc++;
s1.push(x);
if (s1.size() > s2.size()){
int y = s1.top();
s1.pop();
s2.push(y);
}
if (!s1.empty() && !s2.empty()){
int a = s1.top(), b = s2.top();
if (a > b){
s1.pop();
s2.pop();
s1.push(b);
s2.push(a);
}
}
it = lower_bound(imp.begin(), imp.end(), x);
int j = (int) (it - imp.begin()) + 1;
upd(j, x);
}
ll get(){
if (s2.empty()) return 0;
int x = (cc % 2) ? s2.top() : s1.top();
it = lower_bound(imp.begin(), imp.end(), x);
int j = (int) (it - imp.begin()) + 1;
pil p1 = get(1, j), p2 = get(j + 1, n);
return (1LL * x * p1.ff - p1.ss) + (p2.ss - 1LL * x * p2.ff);
}
void clear(){
for (int i = 0; i < 4 * n; i++){
t[i] = {0, 0};
}
while (!s1.empty()) s1.pop();
while (!s2.empty()) s2.pop();
}
};
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int k, n; cin>>k>>n;
vector<pii> all;
ll out = 0;
while (n--){
char t1, t2; int x1, y1; cin>>t1>>x1>>t2>>y1;
if (t1 == t2){
out += abs(x1 - y1);
continue;
}
if (x1 > y1) swap(x1, y1);
all.pb({x1, y1});
}
if (all.empty()){
cout<<out<<"\n";
return 0;
}
n = (int) all.size();
vector<int> imp;
for (auto [x, y]: all){
imp.pb(x); imp.pb(y);
}
ll mn = inf;
if (k == 1){
sort(imp.begin(), imp.end());
int x = imp[(int) (imp.size() - 1) / 2];
ll sum = 0;
for (int i: imp){
sum += abs(i - x);
}
mn = sum + n;
}
else {
vector<pii> f;
for (int i = 0; i < n; i++){
f.pb({all[i].ff + all[i].ss, i});
}
sort(f.begin(), f.end());
vector<ll> f1(n + 1);
DS T; T.init(imp);
for (int i = 1; i <= n; i++){
auto [x, y] = all[f[i - 1].ss];
T.add(x); T.add(y);
f1[i] = T.get();
}
vector<ll> f2(n + 2);
T.clear();
for (int i = n; i > 0; i--){
auto [x, y] = all[f[i - 1].ss];
T.add(x); T.add(y);
f2[i] = T.get();
}
for (int i = 0; i <= n; i++){
mn = min(mn, f1[i] + f2[i + 1] + n);
}
}
cout<<out + mn<<"\n";
}
