#include <bits/stdc++.h>
#define pii pair<int, int>
#define f first
#define s second
#define pb push_back
#define mp make_pair
#define ll long long
#define ld long double
#define sz(v) int(v.size())
#define all(v) v.begin(), v.end()
#define vec vector<int>
#define dead not_bad
#define bad gooood
#define left not_right
#define y1 what
using namespace std;
const int N = (int) 2e5 + 10;
const int M = (int) 2e6;
const ll LINF = (ll) 2e18;
const int INF = (int) 1e9 + 7;
const int ALPHA = 26;
const int mod = INF;
const double PI = 3.14159265359;
const ld EPS = (ld) 1e-12;
const int nx[4] = {0, 0, -1, 1};
const int ny[4] = {1, -1, 0, 0};
vector<ll> a, b;
ll get(ll x) {
ll cur = 0;
for (int i = 0; i < sz(a); i++) {
if (a[i] <= x && x <= b[i]) {
cur += b[i] - a[i];
} else if (a[i] > x) {
cur += a[i] + b[i] - 2 * x;
} else if (b[i] < x) {
cur += 2 * x - (a[i] + b[i]);
} else {
assert(0);
}
}
return cur;
}
ll solve() {
ll l = 0, r = INF;
while (r - l > 2) {
ll m1 = l + (r - l) / 3;
ll m2 = r - (r - l) / 3;
if (get(m1) > get(m2)) {
l = m1;
} else {
r = m2;
}
}
ll ans = LINF;
for (ll i = l; i <= r; i++) {
ans = min(ans, get(i));
}
return ans + sz(a);
}
int k, n;
int main() {
#define fn "teams"
#ifdef witch
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#else
//freopen(fn".in", "r", stdin);
//freopen(fn".out", "w", stdout);
#endif
ll ans = 0;
cin >> k >> n;
for (int i = 1; i <= n; i++) {
char ta, tb;
ll x1, x2;
cin >> ta >> x1 >> tb >> x2;
//cout << ta << ' ' << x1 << ' ' << tb << ' ' << x2 << endl;
if (x1 > x2)
swap(x1, x2);
if (ta == tb) {
ans += x2 - x1;
} else {
a.pb(x1);
b.pb(x2);
}
}
cout << ans + solve();
return 0;
}
