#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const int mod = 1000 * 1000 * 1000 + 7;
const int INF = 1e9 + 100;
const ll LINF = 1e18 + 100;
#ifdef DEBUG
#define dbg(x) cout << #x << " = " << (x) << endl << flush;
#define dbgr(s, f) { cout << #s << ": "; for (auto _ = (s); _ != (f); _++) cout << *_ << ' '; cout << endl << flush; }
#else
#define dbg(x) ;
#define dbgr(s, f) ;
#endif
#define FOR(i, a, b) for (int i = (a); i < (int)(b); i++)
#define fast_io ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define all(x) (x).begin(), (x).end()
#define pb push_back
#define mp make_pair
#define fr first
#define sc second
#define endl '\n'
#define MAXN 100100
int k, n;
int lft[MAXN], rgt[MAXN];
char z1[MAXN], z2[MAXN];
ll ans, res[MAXN];
vector<int> vec;
priority_queue<int> pql;
priority_queue<int, vector<int>, greater<int>> pqr;
ll lsum, rsum;
void add(int x)
{
if (pqr.size() && x >= pqr.top()) pqr.push(x), rsum += x;
else pql.push(x), lsum += x;
if (pqr.size() > pql.size())
{
pql.push(pqr.top());
lsum += pqr.top();
rsum -= pqr.top();
pqr.pop();
}
else if (pql.size() > pqr.size() + 1)
{
pqr.push(pql.top());
lsum -= pql.top();
rsum += pql.top();
pql.pop();
}
}
inline ll getres(void)
{
ll mid = pql.top();
return mid * pql.size() - lsum + rsum - mid * pqr.size();
}
int32_t main(void)
{
fast_io;
cin >> k >> n;
FOR(i, 0, n)
{
cin >> z1[i] >> lft[i] >> z2[i] >> rgt[i];
if (lft[i] > rgt[i]) swap(lft[i], rgt[i]);
if (z1[i] == z2[i])
ans += rgt[i] - lft[i];
else
vec.pb(i), ans++;
}
sort(all(vec), [&](int x, int y){ return (lft[x] + rgt[x]) < (lft[y] + rgt[y]); });
FOR(i, 1, vec.size())
{
add(lft[vec[i - 1]]);
add(rgt[vec[i - 1]]);
res[i] += getres();
}
// clear
while (pql.size()) pql.pop();
while (pqr.size()) pqr.pop();
lsum = rsum = 0;
for (int i = (int)vec.size() - 1; i >= 0; i--)
{
add(lft[vec[i]]);
add(rgt[vec[i]]);
res[i] += getres();
}
if (k == 2)
cout << *min_element(res, res + vec.size()) + ans << endl;
else cout << res[0] + ans << endl;
return 0;
}
