// to live is to die
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
typedef long long int ll;
typedef unsigned long long ull;
typedef pair<int, int> pi;
typedef pair<ll, ll> pl;
typedef vector<int> vi;
typedef vector<long long> vl;
typedef vector<pair<int, int>> vpi;
typedef vector<pair<ll, ll>> vpl;
#define Clear(a, n) \
for (int i = 0; i <= n; i++) { \
a[i] = 0; \
}
#define clearMat(a, n, m, d) \
for (int i = 0; i <= n; i++) { \
for (int j = 0; j <= m; j++) a[i][j] = d; \
}
#define YES cout << "YES\n"
#define NO cout << "NO\n"
#define PB push_back
#define PF push_front
#define MP make_pair
#define F first
#define S second
#define rep(i, n) for (int i = 0; i < n; i++)
#define repe(i, j, n) for (int i = j; i < n; i++)
#define SQ(a) (a) * (a)
#define rep1(i, n) for (int i = 1; i <= n; i++)
#define Rrep(i, start, finish) for (int i = start; start >= finish; i--)
#define forn(i, Start, End, step) for (int i = Start; i <= End; i += step)
#define rforn(i, Start, End, step) for (int i = Start; i >= End; i -= step)
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
// ll arr[SIZE];
/*
how to find n % mod ; n < 0?
x = (n+mod)%mod
if(x < 0) x += mod;
*/
void __print(int x) { cerr << x; }
void __print(long x) { cerr << x; }
void __print(long long x) { cerr << x; }
void __print(unsigned x) { cerr << x; }
void __print(unsigned long x) { cerr << x; }
void __print(unsigned long long x) { cerr << x; }
void __print(float x) { cerr << x; }
void __print(double x) { cerr << x; }
void __print(long double x) { cerr << x; }
void __print(char x) { cerr << '\'' << x << '\''; }
void __print(const char *x) { cerr << '\"' << x << '\"'; }
void __print(const string &x) { cerr << '\"' << x << '\"'; }
void __print(bool x) { cerr << (x ? "true" : "false"); }
template <typename T, typename V>
void __print(const pair<T, V> &x) {
cerr << '{';
__print(x.first);
cerr << ',';
__print(x.second);
cerr << '}';
}
template <typename T>
void __print(const T &x) {
int f = 0;
cerr << '{';
for (auto &i : x) cerr << (f++ ? "," : ""), __print(i);
cerr << "}";
}
void _print() { cerr << "]\n"; }
template <typename T, typename... V>
void _print(T t, V... v) {
__print(t);
if (sizeof...(v)) cerr << ", ";
_print(v...);
}
#ifndef ONLINE_JUDGE
#define db(x...) \
cerr << "[" << #x << "] = ["; \
_print(x)
#else
#define db(x...)
#endif
// order_of_key(k): # of elements less than k (which is the index of x = k)
// find_by_order(k); iterator of the k-th element
template <typename T>
using ordered_set =
tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template <typename T>
using ordered_multiset = tree<T, null_type, less_equal<T>, rb_tree_tag,
tree_order_statistics_node_update>;
template <class T>
bool ckmin(T &a, const T &b) {
return b < a ? a = b, 1 : 0;
}
template <class T>
bool ckmax(T &a, const T &b) {
return a < b ? a = b, 1 : 0;
}
template <typename T>
istream &operator>>(istream &in, vector<T> &a) {
for (auto &x : a) in >> x;
return in;
};
template <typename T>
ostream &operator<<(ostream &out, vector<T> &a) {
for (auto &x : a) out << x << ' ';
return out;
};
// priority_queue<data type , the container that would hold the values ,
// greater<pair<int,int>>> greater means that we want the smallest value on top
// less means that we want the largest
// x ^ (n) mod m = ( (x mod m)^(n) ) mod m
ll const MAX = 1e18 + 1;
ll const oo = 3e18 + 1;
ll const INF = 1e9 + 10;
const ll MOD = 1e9 + 7;
ll const SIZE = 2e5 + 900;
const int LOG = 20;
template <typename T, typename T2>
T add(T X, T2 Y) {
X += Y;
if (X >= MOD) {
X -= MOD;
}
return X;
}
template <typename T, typename T2>
T sub(T X, T2 Y) {
X -= Y;
if (X < 0) X += MOD;
return X;
}
template <typename T, typename T2>
T mult(T X, T2 Y) {
return (X % MOD) * (Y % MOD) % MOD;
}
void setIO(string s) {
freopen((s + ".in").c_str(), "r", stdin);
freopen((s + ".out").c_str(), "w", stdout);
}
// bool operator <s (const type & obj1 , const type & obj2){....}
void solve()
{
int K , N;
cin >> K >> N;
ll same = 0 , sumL{} , sumR{};
priority_queue<ll>L;
priority_queue<ll , vector<ll> , greater<ll>>R;
vpl V = {{0 , 0}};
rep(i , N)
{
char a , b ;
ll s , t;
cin >> a >> s >> b >> t;
if(a == b)
{
same += abs(s - t);
}else{
V.PB({s , t});
}
}
//find median of All Ts and Ss
auto handle_insert = [&](ll X)->void
{
ll mid = L.empty() ? oo : L.top();
if(X <= mid)
{
L.push(X);
sumL += X;
}else{
R.push(X);
sumR += X;
}
if(R.size() + 1 < L.size())
{
ll x = L.top();
L.pop();
R.push(x);
sumR += x;
sumL -= x;
}else if(L.size() < R.size())
{
ll x = R.top();
R.pop();
L.push(x);
sumR -= x;
sumL += x;
}
};
sort(all(V) , [&](pl p1 , pl p2)->bool
{
return p1.F + p1.S < p2.F + p2.S;
});
ll add = same + (ll)V.size() - 1;
vl pref(N + 10);
int _N = (int)V.size() - 1;
for(int i = 1; i <= _N ; i ++)
{
handle_insert(V[i].F);
handle_insert(V[i].S);
pref[i] = sumR - sumL;
}
ll answer = pref[_N];
if(K == 2)
{
while(R.size())R.pop();
while(L.size())L.pop();
sumL = 0 ; sumR = 0;
for(int i = _N ; i >= 1 ; i--)
{
handle_insert(V[i].F);
handle_insert(V[i].S);
answer = min(answer , sumR - sumL + pref[i - 1]);
}
}
cout << answer + add << "\n";
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int T = 1;
// setIO("hayfeast");
// cin >> T;
while (T--) {
solve();
}
return 0;
}
