//Huyduocdithitp
#include <bits/stdc++.h>
typedef long long ll;
#define endl '\n'
#define yes cout<<"YES"<<endl;
#define no cout<<"NO"<<endl;
#define fi first
#define se second
#define pii pair<ll, ll>
#define inf 1e18
#define faster ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
#define MP make_pair
#define TASK "ghuy4g"
#define start if(fopen(TASK".inp","r")){freopen(TASK".inp","r",stdin);freopen(TASK".out","w",stdout);}
#define LOG 19
#define N 500005
using namespace std;
ll k, n;
ll ans_goc = 0;
pii a[N];
vector<ll> nenSo;
void sub1() {
ll ans = inf;
sort(a + 1, a + 1 + n);
ll sum = 0;
ll cur_p = -1;
ll cnt_r = n, cnt_l = 0;
for (int i = 1; i <= n; i ++) {
ll l = a[i].fi, r = a[i].se;
//cout << i << " " << l << " " << r << " " << sum << endl;
sum += (r - l) + min(abs(r - cur_p), abs(l - cur_p)) * 2 + 1;
}
//cout << "sum bd: " << sum << endl;
ans = min(ans, sum);
ll id = 1;
priority_queue<pii, vector<pii>, greater<pii>> pq;
for (int i = 1; i < nenSo.size(); i ++) {
ll nxt_p = nenSo[i];
while (pq.size() && pq.top().fi < nxt_p) {
cnt_l ++ ;
pq.pop();
}
sum -= cnt_r * (nxt_p - cur_p) * 2;
sum += cnt_l * (nxt_p - cur_p) * 2;
while (id <= n && a[id].fi <= nxt_p) {
cnt_r -- ;
pq.push({a[id].se, id});
id ++ ;
}
//cout << i << " " << nxt_p << " " << sum << endl;
ans = min(ans, sum);
cur_p = nxt_p;
}
cout << ans + ans_goc;
}
signed main(void) {
faster;
ll curid = 0;
cin >> k >> n;
for (int i = 1; i <= n; i ++) {
char bs1, bs2; ll p1, p2;
cin >> bs1 >> p1 >> bs2 >> p2;
if (bs1 == bs2) {
ans_goc += abs(p1 - p2);
continue;
}
curid ++ ;
if (p1 > p2) swap(p1, p2);
a[curid] = {p1, p2};
nenSo.push_back(p1);
nenSo.push_back(p2);
}
n = curid;
nenSo.push_back(-inf);
sort(nenSo.begin(), nenSo.end());
nenSo.resize(unique(nenSo.begin(), nenSo.end()) - nenSo.begin());
if (k == 1) {
sub1();
}
return 0;
}
