// Born_To_Laugh - Hughie Do
#include <bits/stdc++.h>
#define alle(AC) AC.begin(), AC.end()
#define fi first
#define se second
using namespace std;
typedef long long ll;
[[maybe_unused]] const int MOD = 998244353, INF = 1e9 + 7;
const int maxn = 2e5 + 10;
int m, k, n, a[maxn], b[maxn];
ll basecost;
vector<int> temp, ids[maxn]; // pp that have a = x | b = x
inline int get_pos(int x){
return lower_bound(alle(temp), x) - temp.begin();
}
namespace sub1
{
bool check(){
return k == 1;
}
void solve(){
int cntl = 0, cntr = n;
int lsti = 0;
ll ans = 3e18 + 7;
ll cost = 0;
for(int i=1; i<=n; ++i) cost += a[i] * 2;
for(int i=1; i<=temp.size() - 1; ++i){
int nxti = temp[i];
cost += cntl * (nxti - lsti) * 2;
cost -= cntr * (nxti - lsti) * 2;
for(auto &elm: ids[i]){
if(nxti == a[elm])cntr--;
if(nxti == b[elm])cntl++;
}
ans = min(ans, cost + basecost);
lsti = nxti;
}
cout << ans << '\n';
}
}
namespace sub2
{
void solve(){
ll ans = 3e18 + 7;
for(int i=1; i < temp.size() - 1; ++i){
int nxti = temp[i];
ll costi = 0;
for(int j=1; j<=n; ++j){
if(b[j] <= nxti) costi += (nxti - b[j]) * 2;
}
//qr j
ll cost = 0;
int cntl = 0, cntr = 0;
int lst = temp[i + 1];
for(int j=1; j<=n; ++j){
if(a[j] <= nxti) continue;
cntr++;
cost += (a[j] - lst) * 2;
}
//
priority_queue<pair<int, int>, vector<pair<int, int>>, greater<>> pq;
for(int j=i + 1; j <= temp.size() - 1; ++j){
int nxt = temp[j];
while(!pq.empty()){
if(nxt < pq.top().fi) break;
int id = pq.top().se;
cost -= (lst - b[id]) * 2;
cost += (a[id] - nxti) * 2;
pq.pop();
cntl--;
}
cost += cntl * (nxt - lst) * 2;
cost -= cntr * (nxt - lst) * 2;
for(auto &elm: ids[j]){
if(a[elm] <= nxti) continue;
if(nxt == a[elm]) cntr--;
if(nxt == b[elm]){
cntl++;
pq.push({b[elm] + a[elm] - nxti, elm});
}
}
ans = min(ans, basecost + costi + cost);
lst = nxt;
}
}
cout << ans << '\n';
}
}
void solve(){
n = 0; cin >> k >> m; basecost = 0;
temp.assign(1, -INF);
for(int i=1; i<=m; ++i){
int s, t;
char p, q;
cin >> p >> s >> q >> t;
if(p == q) basecost += abs(s - t);
else{
if(s > t) swap(s, t);
a[++n] = s; b[n] = t;
basecost += t - s + 1;
temp.push_back(s);
temp.push_back(t);
}
}
sort(alle(temp));
temp.erase(unique(alle(temp)), temp.end());
for(int i=1; i<=n; ++i){
ids[get_pos(a[i])].push_back(i);
ids[get_pos(b[i])].push_back(i);
}
if(n <= k){
cout << basecost << '\n';
return;
}
if(sub1::check()) sub1::solve();
else sub2::solve();
}
signed main(){
// freopen("inp.txt", "r", stdin);
// freopen("out.txt", "w", stdout);
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
solve();
}
