#pragma GCC optimize("O3")
#pragma GCC target("popcnt")
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define Waimai ios::sync_with_stdio(false),cin.tie(0)
#define FOR(x,a,b) for(int x=a,I=b;x<=I;x++)
#define pb emplace_back
#define F first
#define S second
const int SIZE = 1e5 + 5;
int n, k;
int a[2 * SIZE];
ll ans, sum[SIZE];
pair<int, int> p[SIZE];
ll lsum, rsum;
int lcnt, rcnt, mid;
priority_queue<int> lpq;
priority_queue<int, vector<int>, greater<int>> rpq;
void Add (int x) {
if (lpq.empty() || x <= lpq.top()) {
lcnt++;
lsum += x;
lpq.push (x);
} else {
rcnt++;
rsum += x;
rpq.push (x);
}
while (rpq.size() > lpq.size()) {
int y = rpq.top();
rpq.pop();
rcnt--;
rsum -= y;
lpq.push (y);
lcnt++;
lsum += y;
}
while (lpq.size() > rpq.size() + 1) {
int y = lpq.top();
lpq.pop();
lcnt--;
lsum -= y;
rpq.push (y);
rcnt++;
rsum += y;
}
mid = lpq.top();
}
void solve() {
cin >> k >> n;
if (k == 1) {
int siz = 0;
FOR (i, 1, n) {
char cx, cy;
int x, y;
cin >> cx >> x >> cy >> y;
if (cx == cy) ans += abs (x - y);
else {
ans++;
a[++siz] = x;
a[++siz] = y;
}
}
n = siz;
nth_element (a + 1, a + (n + 1) / 2, a + n + 1);
mid = a[(n + 1) / 2];
FOR (i, 1, n) ans += abs (a[i] - mid);
cout << ans << '\n';
return;
}
int siz = 0;
FOR (i, 1, n) {
char cx, cy;
int x, y;
cin >> cx >> x >> cy >> y;
if (cx == cy) ans += abs (x - y);
else {
ans++;
p[++siz] = {x, y};
}
}
n = siz;
sort (p + 1, p + n + 1, [] (auto p1, auto p2) {
return p1.F + p1.S < p2.F + p2.S;
});
FOR (i, 1, n) {
auto [x, y] = p[i];
Add (x), Add (y);
sum[i] += (lcnt - rcnt) * mid - lsum + rsum;
}
lcnt = rcnt = 0;
lsum = rsum = 0;
lpq = {}, rpq = {};
for (int i = n; i >= 1; i--) {
auto [x, y] = p[i];
Add (x), Add (y);
sum[i - 1] += (lcnt - rcnt) * mid - lsum + rsum;
}
cout << ans + *min_element (sum, sum + n + 1) << '\n';
}
int main() {
Waimai;
solve();
}
