//Never stop trying
/*#pragma GCC target ("avx2")
#pragma GCC optimize ("Ofast")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")*/
#include "bits/stdc++.h"
using namespace std;
#define boost ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0)
typedef long long ll;
#define int ll
typedef string str;
typedef double db;
typedef long double ld;
typedef pair<int, int> pi;
#define fi first
#define se second
typedef vector<int> vi;
typedef vector<pi> vpi;
typedef vector<str> vs;
typedef vector<ld> vd;
#define pb push_back
#define eb emplace_back
#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
#define endl "\n"
#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
const int MOD = 1e9 + 7; //998244353
const ll INF = 1e18;
const int MX = 2e5 + 10;
const int nx[4] = {0, 0, 1, -1}, ny[4] = {1, -1, 0, 0}; //right left down up
template<class T> using V = vector<T>;
template<class T> bool ckmin(T& a, const T& b) { return a > b ? a = b, 1 : 0; }
template<class T> bool ckmax(T& a, const T& b) { return a < b ? a = b, 1 : 0; }
ll cdiv(ll a, ll b) { return a / b + ((a ^ b) > 0 && a % b); } // divide a by b rounded up
//constexpr int log2(int x) { return 31 - __builtin_clz(x); } // floor(log2(x))
mt19937 rng(chrono::system_clock::now().time_since_epoch().count());
//mt19937_64 rng(chrono::system_clock::now().time_since_epoch().count());
ll random(ll a, ll b){
return a + rng() % (b - a + 1);
}
#ifndef LOCAL
#define cerr if(false) cerr
#endif
#define dbg(x) cerr << #x << " : " << x << endl;
#define dbgs(x,y) cerr << #x << " : " << x << " / " << #y << " : " << y << endl;
#define dbgv(v) cerr << #v << " : " << "[ "; for(auto it : v) cerr << it << ' '; cerr << ']' << endl;
#define here() cerr << "here" << endl;
void IO() {
#ifdef LOCAL
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#endif
}
int K,N;
vpi vec;
vi pref(MX,0);
bool cmp(pi a, pi b){
return a.fi+a.se<b.fi+b.se;
}
int l,r;
priority_queue<int> lpq;
priority_queue<int,vi,greater<int>> rpq;
void add(int x){
int med=(sz(lpq)?lpq.top():INF);
if(x<=med){
lpq.push(x);
l+=x;
}
else{
rpq.push(x);
r+=x;
}
if(sz(lpq)>sz(rpq)+1){
int cur=lpq.top();
lpq.pop();
rpq.push(cur);
l-=cur;
r+=cur;
}
else if(sz(lpq)<sz(rpq)){
int cur=rpq.top();
rpq.pop();
lpq.push(cur);
r-=cur;
l+=cur;
}
}
int32_t main() {
boost; IO();
cin>>K>>N;
int ans,same=0;
vec.eb(0,0);
FOR(i,0,N){
char a,b; int x,y; cin>>a>>x>>b>>y;
if(a==b) same+=abs(x-y);
else vec.eb(x,y);
}
sort(all(vec),cmp);
N=sz(vec)-1; same+=N;
r=l=0;
FOR(i,1,N+1){
add(vec[i].fi);
add(vec[i].se);
pref[i]=r-l;
}
ans=pref[N];
if(K==2){
while(sz(lpq)) lpq.pop();
while(sz(rpq)) rpq.pop();
l=r=0;
ROF(i,1,N+1){
add(vec[i].fi);
add(vec[i].se);
ckmin(ans,r-l+pref[i-1]);
}
}
ans+=same;
cout << ans << endl;
return 0;
}
/* Careful!!!
.Array bounds
.Infinite loops
.Uninitialized variables / empty containers
.Multisets are shit
Some insights:
.Binary search
.Graph representation
.Write brute force code
.Change your approach
*/
