#include<iostream>
#include<stack>
#include<map>
#include<vector>
#include<string>
#include<unordered_map>
#include <queue>
#include<cstring>
#include<limits.h>
#include<cmath>
#include<set>
#include<algorithm>
#include<bitset>
#include<stack>
using namespace std;
#define ll long long
#define f first
#define endl "\n"
#define s second
#define pii pair<int,int>
#define pppiiii pair<pii,pii>
#define ppii pair<int,pii>
#define all(x) x.begin(),x.end()
#define pb push_back
#define mp make_pair
#define lb lower_bound
#define ub upper_bound
#define fastio ios::sync_with_stdio(false);cin.tie(NULL);
#pragma GCC optimize ("03,unroll-loops")
#define int long long
const ll mod=998244353,mxn=3*8e4+5,lg=30,inf=1e18,minf=-1e9,Mxn=100000;
int32_t main(){
fastio
int k,n;cin>>k>>n;
if(k!=1)return 0;
int ans=0;
vector<int>v;
pair<char,int>a,b;
for(int i=0;i<n;i++){
cin>>a.f>>a.s>>b.f>>b.s;
if(a.f==b.f)ans+=abs(a.s-b.s);
else v.pb(b.s),v.pb(a.s),ans++;
}
sort(all(v));
for(auto i:v)ans+=abs(v[v.size()/2]-i);
cout<<ans;
}
