//اللهم منزل الكتاب ومجري السحاب وهْازِم الأحزاب، اهزمهم وانصرنا عليهم
//اللهم علمنا ما ينفعنا، وانفعنا بما علمتنا، وزدنا علما
#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define pb push_back
#define el '\n'
using namespace std;
using namespace __gnu_pbds;
#define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>
template<class T>
using ordered_multiset = tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long ll;
const ll OO = 1e9;
const int N = 1e5 + 1, mod = 1e9 + 7;
void solve() {
ll ans = 0;
int n, k;
cin >> k >> n;
vector<int> l, r;
for (int i = 0; i < n; ++i) {
char a, b;
int q, t;
cin >> a >> q >> b >> t;
if (a == b) {
ans += abs(q - t);
continue;
}
if (a == 'B') {
swap(a, b);
swap(q, t);
}
l.push_back(q);
r.push_back(t);
}
if (k == 1) {
vector<int> sorted = l;
for (auto i: r)sorted.pb(i);
sort(sorted.begin(), sorted.end());
int med = sorted[sorted.size() / 2];
for (int i = 0; i < l.size(); i++) {
ans += abs(l[i] - med) + 1 + abs(r[i] - med);
}
cout << ans;
}
else {
vector<int> sorted = l;
sort(sorted.begin(), sorted.end());
int med1 = sorted[sorted.size()/2];
sorted = r;
sort(sorted.begin(), sorted.end());
int med2 = sorted[sorted.size()/2];
for (int i = 0; i < l.size(); i++) {
ans += min(abs(l[i] - med1) + 1 + abs(r[i] - med1),
abs(l[i] - med2) + 1 + abs(r[i] - med2));
}
cout << ans;
}
}
int main() {
cin.tie(0)->sync_with_stdio(0);
#ifdef LOCAL
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
freopen("error.txt", "w", stderr);
#endif
int t = 1;
// cin >> t;
while (t--) {
solve();
}
}
