#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define fi first
#define se second
#define pii pair<int,int>
#define pll pair<long long,long long>
#define pb push_back
#define debug(x) cerr<<#x<<"="<<x<<endl
#define pq priority_queue
#define inf 1ll<<60
#define rep(i,a,b) for (ll i=a;i<(b);i++)
#define MP make_pair
#define SZ(x) (int(x.size()))
#define mod 1000000007
#define ALL(x) x.begin(),x.end()
#define endl "\n"
void inc(ll &a,ll b) {a=(a+b)%mod;}
void dec(ll &a,ll b) {a=(a-b+mod)%mod;}
int lowbit(ll x) {return x&(-x);}
vector<ll>alist;
ll k,n;
const ll maxn = 1e5+5;
ll pre[maxn],suff[maxn];
ll lsum=0,rsum=0;
multiset<ll>lo,hi;
void maintain(){
while(SZ(lo)>SZ(hi)+1){
ll tmp=*(--lo.end());
hi.insert(*(--lo.end()));
rsum+=tmp;
lo.erase(--lo.end());
lsum-=tmp;
}
while(SZ(hi)>SZ(lo)){
ll tmp=*hi.begin();
lo.insert(*hi.begin());
lsum+=tmp;
hi.erase(hi.begin());
rsum-=tmp;
}
}
void add(ll x){
if(hi.empty() or *hi.begin()>x)lo.insert(x),lsum+=x;
else hi.insert(x),rsum+=x;
maintain();
}
void rem(ll x){//remove element
if(lo.find(x)!=lo.end())lo.erase(lo.find(x)),lsum-=x;
else if(hi.find(x)!=hi.end())hi.erase(hi.find(x)),rsum-=x;
maintain();
}
ll med(){// lo contains ceil(n/2),hi contains floor(n/2)
return *(--lo.end());
}
void reset(){
lo.clear();
hi.clear();
lsum=0;
rsum=0;
return;
}
bool cmp(pll a,pll b){//si+ti<sj+tj
return a.fi+a.se<b.fi+b.se;
}
int main(){
ios::sync_with_stdio(0);cin.tie(0);
//freopen("i.txt", "r", stdin);
cin>>k>>n;
if(k==1){
vector<ll>s,t,b;
ll ans=0;
rep(i,0,n){
char pp,qq;
ll ss,tt;
cin>>pp>>ss>>qq>>tt;
if(pp==qq)ans+=abs(tt-ss);
else{
ans++;//cross bridge
b.pb(ss);b.pb(tt);
s.pb(ss);
t.pb(tt);
}
}
sort(ALL(b));
ll mid=0;
if(SZ(b)>0)mid=b[SZ(b)/2];
ll dist=0;
rep(i,0,SZ(s)){
dist+=abs(mid-s[i])+abs(mid-t[i]);
}
cout<<dist+ans;
return 0;
}
ll tmp=0;
vector<pll>alist;
rep(i,0,n){
char pp,qq;
ll ss,tt;
cin>>pp>>ss>>qq>>tt;
if(pp==qq)tmp+=abs(tt-ss);//no need care about this citizen afterwards alr
else{
tmp++;//cross bridge
alist.pb(MP(ss,tt));
}
}
sort(ALL(alist),cmp);
n=alist.size();//new n is just all the citizens that have to cross the bridge
rep(i,0,n){//iterate where the bridges are built to split into 2 groups,will def be on an office/house
add(alist[i].fi);
add(alist[i].se);
pre[i]=rsum-lsum;
}
reset();
for(int i=n-1;i>0;i--){
add(alist[i].fi);
add(alist[i].se);
suff[i]=rsum-lsum;
}
ll ans=0,mn=inf;
rep(i,0,n){
mn=min(mn,pre[i]+suff[i+1]);
}
if(mn==inf)ans=tmp;
else ans=mn+tmp;
cout<<ans;
return 0;
}
/*
2 5
B 0 A 4
B 1 B 3
A 5 B 7
B 2 A 6
B 1 A 7
*/
