#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
#define FOR(i, a, b) for(ll i = (ll)a; i <= (ll)b; i++)
#define DEC(i, a, b) for(ll i = (ll)a; i >= (ll)b; i--)
typedef pair<ll, ll> pi;
typedef pair<pi, ll> pii;
typedef pair<ll, pi> ipi;
typedef pair<pi, pi> pipi;
#define f first
#define s second
typedef vector<ll> vi;
typedef vector<pi> vpi;
typedef vector<pii> vpii;
#define pb push_back
#define pf push_front
#define all(v) v.begin(), v.end()
#define size(v) (ll) v.size()
#define disc(v) sort(all(v)); v.resize(unique(all(v)) - v.begin());
#define INF (ll) 1e9 + 100
#define LLINF (ll) 1e18
#define fastio ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define sandybridge __attribute__((optimize("Ofast"), target("arch=sandybridge")))
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count()); //can be used by calling rng() or shuffle(A, A+n, rng)
inline ll rand(ll x, ll y) { ++y; return (rng() % (y-x)) + x; } //inclusivesss
struct seg {
ll a, b, mid;
seg (ll x, ll y) {
a = x, b = y, mid = (a+b)/2;
}
bool operator<(seg x) const {
return mid < x.mid;
}
};
ll k, n, m, a, b, ans, val[2][100005], lsum, rsum;
char x, y;
vector<seg> v;
vi coord;
priority_queue<ll> L;
priority_queue<ll, vi, greater<ll>> R;
int main() {
fastio; cin >> k >> n;
ans = n;
FOR(i, 1, n) {
cin >> x >> a >> y >> b;
if (x == y) ans += abs(b-a) - 1;
else {
v.pb(seg(a, b));
coord.pb(a);
coord.pb(b);
}
}
if (v.empty()) {
cout << ans;
return 0;
}
m = size(v);
v.pb(seg(-1, -1));
sort(all(v));
v.pb(seg(-1, -1));
if (k == 1) {
sort(all(coord));
ll x = coord[size(coord)/2];
for (auto it:coord) ans += abs(it - x);
cout << ans;
return 0;
}
FOR(temp, 0, 1) {
while (!L.empty()) L.pop();
while (!R.empty()) R.pop();
lsum = rsum = 0;
FOR(i, 1, m) {
a = v[i].a, b = v[i].b;
if (L.empty()) {
L.push(min(a, b)), R.push(max(a, b));
lsum += min(a, b), rsum += max(a, b);
} else {
ll med = L.top();
if (a <= med) L.push(a), lsum += a;
else R.push(a), rsum += a;
if (b <= med) L.push(b), lsum += b;
else R.push(b), rsum += b;
}
while (size(R) < size(L)) {
rsum += L.top();
lsum -= L.top();
R.push(L.top());
L.pop();
}
while (size(L) < size(R)) {
lsum += R.top();
rsum -= R.top();
L.push(R.top());
R.pop();
}
assert(size(R) == size(L));
ll med = L.top();
val[temp][i] = med * size(L) - lsum + rsum - med * size(R);
}
reverse(all(v));
}
ll ans2 = LLINF;
FOR(i, 0, m) ans2 = min(ans2, val[0][i] + val[1][m-i]);
cout << ans + ans2;
}
