#include <bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
#define ordered_set tree<int, null_type,less_equal<int>, rb_tree_tag,tree_order_statistics_node_update>
// #pragma GCC optimize("Ofast,unroll-loops,fast-math")
// #pragma GCC target("popcnt,sse3,avx")
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<ll,ll> pll;
#define sz size()
#define ff first
#define ss second
#define all(a) a.begin(),a.end()
#define pb push_back
const int mod = ll(1e9)+7; //(b + (a%b)) % b (to mod -1%(10^9+7) correctly in c++ its -1 but its suppose to be 10^9+6
const ll MOD = 998244353; // (a%mod)*(binpow(b,mod-2,mod) = (a/b)%mod
const int N = ll(2e5)+100;
const int M = ll(2e5) + 100;
const long long inf = 5e18;
//const long double eps = 1e-15L;
ll lcm(ll a, ll b) { return (a / __gcd(a,b))*b; }
ll binpow(ll a, ll b, ll m) { ll res=1; a %= m; while(b>0){ if(b&1)res=(res * a) % m; a=(a * a) % m; b/=2; } return res%m;}
void Freopen(string Key){ freopen((Key+".in").c_str(), "r", stdin); freopen((Key+".out").c_str(), "w", stdout); }
int k, n, m;
pair<int, int> point[N];
bool cmp(pair<int, int> a, pair<int, int> b) {
return (a.ff + a.ss) < (b.ff + b.ss);
}
vector<int> get(int l, int r) {
if(l > r) return {};
vector<int> res;
for(int i = l; i <= r; i ++) res.pb(point[i].ff), res.pb(point[i].ss);
sort(all(res));
return res;
}
void Baizho() {
cin>>k>>n;
long long ex = 0;
for(int i = 1; i <= n; i ++) {
char p, q;
int s, t;
cin>>p>>s>>q>>t;
if(s > t) swap(s, t);
if(p == q) ex += t - s;
else {
ex ++;
point[++m] = {s, t};
}
}
sort(point + 1, point + m + 1, cmp);
long long ans = 0;
if(k == 1) {
vector<int> pos = get(1, m);
int mid = (pos.size()) / 2;
for(auto x : pos) ans += abs(pos[mid] - x);
} else if(k == 2 && m) {
ans = inf;
for(int i = 1; i <= m; i ++) {
vector<int> pos1 = get(1, i), pos2 = get(i + 1, m);
int mid1 = (pos1.size()) / 2, mid2 = (pos2.size()) / 2;
long long res = 0;
for(auto x : pos1) res += abs(pos1[mid1] - x);
for(auto x : pos2) res += abs(pos2[mid2] - x);
ans = min(ans, res);
}
}
cout<<ans + ex;
}
signed main() {
// Freopen("nondec");
ios_base::sync_with_stdio(false);
cin.tie(0);cout.tie(0);
// precalc();
int ttt = 1;
// cin>>ttt;
for(int i=1; i<=ttt; i++) {Baizho(); }
}
