#include <bits/stdc++.h>
#define int long long
#define fi first
#define se second
#define pb push_back
#define faster ios_base::sync_with_stdio(0); cin.tie(0);
using namespace std;
using ll = long long;
using ull = unsigned ll;
using ld = long double;
using pii = pair <int, int>;
using pil = pair <int, ll>;
using pli = pair <ll, int>;
using pll = pair <ll, ll>;
mt19937 Rand(chrono::steady_clock::now().time_since_epoch().count());
ll min(const ll &a, const ll &b){
return (a < b) ? a : b;
}
ll max(const ll &a, const ll &b){
return (a > b) ? a : b;
}
//const ll Mod = 1000000007;
//const ll Mod2 = 999999999989;
//only use when required
const int maxN = 3e5 + 1;
const ll inf = 0x3f3f3f3f3f3f3f3f;
int n, k;
vector <int> val[maxN * 4];
vector <ll> sum[maxN * 4];
vector <int> b;
ll pre[maxN], suf[maxN];
int wt_sz = 1;
struct TNode{
int l, r;
int lp, rp;
TNode(){
l = r = lp = rp = 0;
}
TNode(int _l, int _r) : l(_l), r(_r){};
};
TNode wt[maxN * 4];
void build(int id, auto i, auto j, int l, int r){
wt[id].l = l;
wt[id].r = r;
if (l == r){
return;
}
val[id].pb(0);
sum[id].pb(0);
int mid = (l + r) / 2;
int maxx = l, minn = r;
for (auto it = i; it != j; ++it){
bool t = *it <= mid;
val[id].pb(val[id].back() + t);
sum[id].pb(sum[id].back() + *it * t);
if (t) maxx = max(maxx, *it);
else minn = min(minn, *it);
}
auto p = stable_partition(i, j,[=](const auto &w){
return w <= mid;
});
wt[id].lp = ++wt_sz;
wt[id].rp = ++wt_sz;
build(wt[id].lp, i, p, l, maxx);
build(wt[id].rp, p, j, minn, r);
}
ll get(int k, int i, int j){
if (k == 0) return 0;
--i;
ll res = 0;
int id = 1;
int l = wt[id].l, r = wt[id].r;
while (l < r){
int mid = (l + r) / 2;
if (k <= val[id][j] - val[id][i]){
i = val[id][i];
j = val[id][j];
id = wt[id].lp;
}
else{
res += sum[id][j] - sum[id][i];
k -= val[id][j] - val[id][i];
i -= val[id][i];
j -= val[id][j];
id = wt[id].rp;
}
l = wt[id].l, r = wt[id].r;
}
res += k * l;
return res;
}
void Init(){
cin >> k >> n;
if (k == 1){
ll ans = 0;
vector <ll> v;
for (ll i = 1; i <= n; ++i){
char p, q; ll s, t;
cin >> p >> s >> q >> t;
if (p != q){
++ans;
v.pb(s);
v.pb(t);
}
else{
ans += abs(s - t);
}
}
v.push_back(0);
sort(v.begin(), v.end());
ll m = v.size();
ll tem = LLONG_MAX;
for (ll i = 1; i < m; ++i){
pre[i] = pre[i - 1] + v[i];
}
for (ll i = m - 1; i > 0; --i){
suf[i] = suf[i + 1] + v[i];
}
for (ll i = 1; i < m; ++i){
tem = min(tem, v[i] * (i - 1) - pre[i - 1] + suf[i + 1] - v[i] * (m - i - 1));
}
if (m == 1) tem = 0;
cout << ans + tem;
return;
}
ll ans = 0;
vector <pii> v;
for (int i = 1; i <= n; ++i){
char p, q; int s, t;
cin >> p >> s >> q >> t;
if (p == q) ans += abs(s - t);
else{
++ans; //cost to go through a bridge
v.pb({s, t});
}
}
sort(v.begin(), v.end(),[](const auto &i, const auto &j){
return (i.fi + i.se) / 2 < (j.fi + j.se) / 2;
});
if (v.empty()){
cout << ans; return;
}
if (v.size() == 1){
cout << ans + abs(v[0].fi - v[0].se); return;
}
ll tem = inf;
b.resize(2 * v.size() + 1);
for (int i = 1; i <= v.size(); ++i){
pre[i] = pre[i - 1] + v[i - 1].fi + v[i - 1].se;
}
for (int i = 0; i < v.size(); ++i){
b[i * 2 + 1] = v[i].fi;
b[i * 2 + 2] = v[i].se;
}
build(1, b.begin() + 1, b.end(), *min_element(b.begin(), b.end()), *max_element(b.begin(), b.end()));
for (int i = 0; i < v.size() - 1; ++i){
ll l = get(i + 1, 1, i * 2 + 2);
ll r = get(v.size() - i - 1, i * 2 + 3, v.size() * 2);
tem = min(tem, pre[i + 1] - 2 * l + pre[v.size()] - pre[i + 1] - 2 * r);
}
cout << tem + ans;
}
#define debu
#define taskname "test"
signed main(){
if (fopen(taskname".inp", "r")){
freopen(taskname".inp", "r", stdin);
#ifdef debug
freopen(taskname".out", "w", stdout);
#endif
}
faster;
ll tt = 1;
//cin >> tt;
while (tt--){
Init();
}
if (fopen("timeout.txt", "r")){
ofstream timeout("timeout.txt");
timeout << 1000 * double(clock()) / CLOCKS_PER_SEC;
#ifndef debug
cerr << "\nTime elapsed: " << 1000 * double(clock()) / CLOCKS_PER_SEC << "ms\n";
#endif
}
}
