#include <bits//stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
typedef tree<long long, null_type, less<long long>, rb_tree_tag,
tree_order_statistics_node_update>
ordered_set;
typedef tree<long long, null_type, less_equal<long long>, rb_tree_tag,
tree_order_statistics_node_update>
ordered_multiset;
#define ll long long
#define ld long double
#define iloop(m, h) for (ll i = m; i != h; i += (m < h ? 1 : -1))
#define jloop(m, h) for (auto j = m; j != h; j += (m < h ? 1 : -1))
#define kloop(m, h) for (auto k = m; k != h; k += (m < h ? 1 : -1))
#define lloop(m, h) for (auto l = m; l != h; l += (m < h ? 1 : -1))
#define iloop_(m, h, g) for (auto i = m; i != h; i += g)
#define jloop_(m, h, g) for (auto j = m; j != h; j += g)
#define kloop_(m, h, g) for (auto k = m; k != h; k += g)
#define lloop_(m, h, g) for (auto l = m; l != h; l += g)
#define getchar_unlocked _getchar_nolock // comment before submission
#define pll pair<ll, ll>
#define plll pair<ll, pll>
#define pllll pair<pll, pll>
#define vll vector<ll>
#define qll queue<ll>
#define dll deque<ll>
#define pqll priority_queue<ll>
#define gll greater<ll>
#define INF 1000000000000000
#define MOD1 1000000007
#define MOD2 998244353
#define MOD3 1000000009
mt19937 rng(chrono::system_clock::now().time_since_epoch().count());
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
ll m, n;
cin >> m >> n;
char c[n], d[n];
ll a[n], b[n];
iloop(0, n) cin >> c[i] >> a[i] >> d[i] >> b[i];
if (m == 1) {
vector<ll> v;
ll cans = 0;
iloop(0, n) if (c[i] != d[i]) {v.push_back(a[i]); v.push_back(b[i]); cans++;}
if (v.size()) sort(v.begin(), v.end());
ll val = (v.size() ? v[v.size()/2] : 0);
iloop(0, n) {
if (c[i] == d[i]) cans += abs(a[i]-b[i]);
else cans += abs(a[i]-val) + abs(b[i]-val);
}
cout << cans;
}
else {
vector<pair<ll, pll>> cross;
ll ans = 0;
iloop(0, n) {
if (c[i] == d[i]) ans += abs(a[i]-b[i]);
else cross.push_back({a[i]+b[i], {a[i], b[i]}});
}
sort(cross.begin(), cross.end());
ll m = cross.size();
ll pf[m + 1], sf[m + 1], tmp[m];
priority_queue<ll> pq;
priority_queue<ll, vector<ll>, greater<ll>> pq_;
pf[0] = 0;
iloop(0, m) {
pq.push(cross[i].second.first);
pq.push(cross[i].second.second);
if (pq_.size()) {pq.push(pq_.top()); pq_.pop();}
if (pq_.size()) {pq.push(pq_.top()); pq_.pop();}
while (pq.size() > pq_.size()) {pq_.push(pq.top()); pq.pop();}
tmp[i] = pq.top();
}
priority_queue<ll, vector<ll>, greater<ll>> cq;
priority_queue<ll> cq_;
ll cb = 0, cf = 0, cbc = 0, cfc = 0;
iloop(0, m) {
if (cross[i].second.first > tmp[i]) {cf += cross[i].second.first; cfc++; cq.push(cross[i].second.first);}
else {cb += cross[i].second.first; cbc++; cq_.push(cross[i].second.first);}
if (cross[i].second.second > tmp[i]) {cf += cross[i].second.second; cfc++; cq.push(cross[i].second.second);}
else {cb += cross[i].second.second; cbc++; cq_.push(cross[i].second.second);}
while (cq.size() && cq.top() < tmp[i]) {cfc--; cbc++; cf -= cq.top(); cb += cq.top(); cq_.push(cq.top()); cq.pop();}
while (cq_.size() && cq_.top() > tmp[i]) {cfc++; cbc--; cf += cq_.top(); cb -= cq_.top(); cq.push(cq_.top()); cq_.pop();}
pf[i+1] = cf - cfc*tmp[i] + cbc*tmp[i] - cb;
}
while (pq.size()) pq.pop();
while (pq_.size()) pq_.pop();
sf[m] = 0;
iloop(m-1, -1) {
pq.push(cross[i].second.first);
pq.push(cross[i].second.second);
if (pq_.size()) {pq.push(pq_.top()); pq_.pop();}
if (pq_.size()) {pq.push(pq_.top()); pq_.pop();}
while (pq.size() > pq_.size()) {pq_.push(pq.top()); pq.pop();}
tmp[i] = pq.top();
}
cb = 0, cf = 0, cbc = 0, cfc = 0;
priority_queue<ll> dq;
priority_queue<ll, vector<ll>, greater<ll>> dq_;
iloop(m-1, -1) {
//cout << tmp[i] << ":" << cross[i].second.first << "," << cross[i].second.second << "\n";
if (cross[i].second.first > tmp[i]) {cf += cross[i].second.first; cfc++; dq_.push(cross[i].second.first);}
else {cb += cross[i].second.first; cbc++; dq.push(cross[i].second.first);}
if (cross[i].second.second > tmp[i]) {cf += cross[i].second.second; cfc++; dq_.push(cross[i].second.second);}
else {cb += cross[i].second.second; cbc++; dq.push(cross[i].second.second);}
while (dq.size() && dq.top() > tmp[i]) {cbc--; cfc++; cb -= dq.top(); cf += dq.top(); dq_.push(dq.top()); dq.pop();}
while (dq_.size() && dq_.top() < tmp[i]) {cbc++; cfc--; cb += dq_.top(); cf -= dq_.top(); dq.push(dq_.top()); dq_.pop();}
sf[i] = cf - cfc*tmp[i] + cbc*tmp[i] - cb;
}
//iloop(0, m+1) cout << pf[i] << "," << sf[i] << "\n";
ll cmin = INF;
iloop(0, m+1) cmin = min(cmin, pf[i] + sf[i]);
cout << ans + cmin + m;
}
}
