#define Magic ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define ll long long
#define ld long double
#define en '\n'
#define tsts int tetss; cin >> tetss; while(tetss--)
#define all(a) a.begin() , a.end()
#define pb push_back
#define ld long double
#define fi first
#define se second
ll INF = 1e18;
const int N = 1e6;
const int mod = 998244353;
using namespace std;
using namespace __gnu_pbds;
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>;
// order_of_key(n) - The number of items in a set that are strictly smaller than k
// find_by_order(k) - It returns an iterator to the ith largest element
// abs((x1 - x3) * (y2 - y3) - (x2 - x3) * (y1 - y3)) / 2 = S
ll lcm(ll a, ll b)
{
ll gc = __gcd(a, b);
return a / gc * b;
}
ll binpow (ll a, ll n) {
if (n == 0)
return 1;
if (n % 2 == 1)
return binpow (a, n-1) * a;
else {
ll b = binpow (a, n/2);
return b * b;
}
}
ll binpow_mod(ll a, ll b, ll md)
{
ll res = 1;
a = a % md;
while (b > 0)
{
if (b & 1)
res = (res * a) % md;
a = (a * a) % md;
b >>= 1;
}
return res;
}
ll in() {ll x; cin >> x; return x;};
ll gcd (ll a, ll b, ll & x, ll & y) {
if (a == 0) {
x = 0; y = 1;
return b;
}
ll x1, y1;
ll d = gcd (b%a, a, x1, y1);
x = y1 - (b / a) * x1;
y = x1;
return d;
}
ll gcdinv(ll a, ll b){
ll x, y;
gcd(a, b, x, y);
return x;
}
// -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- чё
void solve(){
ll k, n; cin >> k >> n;
ll ans = 0;
vector<ll> v;
for(ll i = 1; i <= n; ++i){
char a, b;
ll x, y; cin >> a >> x >> b >> y;
if(a == b) ans += abs(x - y);
else{
ans++;
v.pb(x);
v.pb(y);
}
}
sort(all(v));
ll sm1 = 0;
ll sm2 = 0;
ll c1 = 0;
ll c2 = 0;
for(auto g : v){
sm1 += g;
c1++;
}
ll tans = INF;
for(auto g : v){
sm1 -= g;
c1--;
sm2 += g;
c2++;
tans = min(tans, (g * c2 - sm2) + (sm1 - g * c1));
}
if(v.size() == 0) tans = 0;
cout << ans + tans;
}
int main(){
Magic
// freopen ("bomb.in", "r", stdin); freopen("bomb.out", "w", stdout);
// tsts{
solve();
cout << endl;
// }
}
