#include <bits/stdc++.h>
using namespace std;
struct slide_med {
multiset<int> L, R;
void insert(int x) {
if (L.empty()) {
L.insert(x);
return;
}
if (x <= *L.rbegin()) {
if (L.size() == R.size())
L.insert(x);
else if (L.size() > R.size()) {
L.insert(x);
R.insert(*L.rbegin());
L.erase(--L.end());
}
}
else {
if (L.size() == R.size()) {
R.insert(x);
L.insert(*R.begin());
R.erase(R.begin());
}
else if (L.size() > R.size())
R.insert(x);
}
}
void erase(int x) {
if (x <= *L.rbegin()) {
if (L.size() == R.size()) {
L.erase(L.find(x));
L.insert(*R.begin());
R.erase(R.begin());
}
else if (L.size() > R.size())
L.erase(L.find(x));
}
else {
if (L.size() == R.size())
R.erase(R.find(x));
else if (L.size() > R.size()) {
R.erase(R.find(x));
R.insert(*L.rbegin());
L.erase(--L.end());
}
}
}
int median() {
if (L.empty())
return 0;
return *L.rbegin();
}
};
template<class Base>
class Segtree : public Base {
using T = typename Base::T;
using Base::dval;
using Base::merge;
using Base::apply;
protected:
size_t n;
vector<T> tree;
public:
Segtree() = default;
Segtree(size_t _n) { init(_n); }
void init(size_t _n) {
n = _n;
tree.assign(n * 2, dval);
}
void update(int i, T v) {
for (apply(tree[i += n], v); i >>= 1;)
tree[i] = merge(tree[i << 1], tree[i << 1 | 1]);
}
T query(int l, int r) {
T ret = dval;
for (l += n, r += n + 1; l < r; l >>= 1, r >>= 1) {
if (l & 1) ret = merge(ret, tree[l++]);
if (r & 1) ret = merge(ret, tree[--r]);
}
return ret;
}
T operator[](int i) { return tree[i += n]; }
};
struct sum_stinfo {
using T = pair<int, long long>;
const T dval = T(0, 0);
T merge(T a, T b) { return make_pair(a.first + b.first, a.second + b.second); }
void apply(T &a, T b) { a.first += b.first, a.second += b.second; }
};
const size_t MAX_A = 1e9 + 5;
int main() {
ios_base::sync_with_stdio(0); cin.tie(0);
int K, N;
cin >> K >> N;
if (K == 1) {
long long ans = 0;
vector<int> A;
for (int i = 0; i < N; i++) {
char a, b;
int x, y;
cin >> a >> x >> b >> y;
if (a == b) {
ans += abs(x - y);
} else {
A.push_back(x);
A.push_back(y);
}
}
ans += A.size() / 2;
sort(A.begin(), A.end());
int B = A[A.size() / 2];
for (int x : A)
ans += abs(B - x);
cout << ans << '\n';
} else if (K == 2) {
long long ans = 0;
vector<pair<int, int>> A;
for (int i = 0; i < N; i++) {
char a, b;
int x, y;
cin >> a >> x >> b >> y;
if (a == b)
ans += abs(x - y);
else
A.emplace_back(min(x, y), max(x, y));
}
ans += A.size();
sort(A.begin(), A.end(),
[](auto a, auto b) {
return a.first + a.second < b.first + b.second;
}
);
map<int, int> M;
for (auto [x, y] : A)
M[x] = 0, M[y] = 0;
int n = 0;
for (auto &[k, v] : M)
v = n++;
slide_med L, R;
Segtree<sum_stinfo> Lsgt(n), Rsgt(n);
for (auto [x, y] : A) {
R.insert(x);
Rsgt.update(M[x], make_pair(1, x));
R.insert(y);
Rsgt.update(M[y], make_pair(1, y));
}
long long tans = LLONG_MAX;
for (int i = 0; i < A.size(); i++) {
auto [x, y] = A[i];
int Mx = M[x], My = M[y];
L.insert(x);
Lsgt.update(Mx, make_pair(1, x));
L.insert(y);
Lsgt.update(My, make_pair(1, y));
R.erase(x);
Rsgt.update(Mx, make_pair(-1, -x));
R.erase(y);
Rsgt.update(My, make_pair(-1, -y));
long long lmid = L.median(), rmid = R.median();
auto l0 = Lsgt.query(0, M[lmid]), l1 = Lsgt.query(M[lmid] + 1, n - 1);
auto r0 = Rsgt.query(0, M[rmid]), r1 = Rsgt.query(M[rmid] + 1, n - 1);
tans = min(tans, l0.first * lmid - l0.second +
l1.second - l1.first * lmid +
r0.first * rmid - r0.second +
r1.second - r1.first * rmid);
}
ans += (tans == LLONG_MAX ? 0 : tans);
cout << ans << '\n';
}
}
