#include <bits/stdc++.h>
#include <bits/extc++.h>
using namespace __gnu_pbds;
using namespace std;
#define ll long long
#define pll pair<ll,ll>
#define pii pair<int,int>
#define fs first
#define sc second
#define tlll tuple<ll,ll,ll>
template<typename T>
using ordered_set = tree<T,null_type,less<T>,rb_tree_tag,tree_order_statistics_node_update>;
const int mxn = 2e5+10;
int N,K;
struct BIT{
ll bit[mxn];
BIT(){}
void modify(int p,int v){
for(;p<mxn;p+=p&-p)bit[p] += v;
return;
}
ll getval(int s,int e){
ll re = 0;
for(;e>0;e-= e&-e)re += bit[e];
s--;
for(;s>0;s-= s&-s)re -= bit[s];
return re;
}
};
namespace S1{
vector<ll> v;
void GO(){
ll ans = 0;
for(int i = 0;i<N;i++){
char s1,s2;
int p1,p2;
cin>>s1>>p1>>s2>>p2;
if(s1 == s2)ans += abs(p2-p1);
else{
v.push_back(p1);
v.push_back(p2);
}
}
sort(v.begin(),v.end());
ll cen = 0;
if(!v.empty())cen = v[v.size()/2];
for(auto &i:v)ans += abs(cen-i);
ans += v.size()>>1;
cout<<ans<<'\n';
return;
}
}
namespace S2{
vector<int> all;
struct DS{
DS(){}
BIT cnt,sum;
ordered_set<pii> st;
int ptr = 0;
void add(int k){
st.insert(pii(k,ptr++));
cnt.modify(k,1);
sum.modify(k,all[k]);
}
void del(int k){
auto it = st.lower_bound(pii(k,-1));
st.erase(st.find(*it));
cnt.modify(k,-1);
sum.modify(k,-all[k]);
}
ll getval(){
if(st.empty())return 0;
ll cen = st.find_by_order(st.size()/2)->fs;
ll lsum = cen*cnt.getval(0,cen)-sum.getval(0,cen);
ll rsum = sum.getval(cen+1,mxn-1)-cen*cnt.getval(cen+1,mxn-1);
return lsum+rsum;
}
};
DS dl,dr;
vector<pll> v;
void GO(){
all.push_back(-1);
ll ans = 0;
for(int i = 0;i<N;i++){
char s1,s2;
int p1,p2;
cin>>s1>>p1>>s2>>p2;
if(s1 == s2){
ans += abs(p1-p2);
}
else{
if(p1>p2)swap(p1,p2);
all.push_back(p1);
all.push_back(p2);
v.push_back(pll(p1,p2));
}
}
sort(all.begin(),all.end());
all.erase(unique(all.begin(),all.end()),all.end());
sort(v.begin(),v.end(),[](pll a,pll b){return a.fs+a.sc<b.fs+b.sc;});
ans += v.size();
for(auto &i:v){
i.fs = lower_bound(all.begin(),all.end(),i.fs)-all.begin();
i.sc = lower_bound(all.begin(),all.end(),i.sc)-all.begin();
dr.add(i.fs);
dr.add(i.sc);
}
ll tans = 1e18;
tans = dl.getval()+dr.getval();
for(auto &i:v){
dr.del(i.fs);
dr.del(i.sc);
dl.add(i.fs);
dl.add(i.sc);
tans = min(tans,dl.getval()+dr.getval());
}
cout<<ans+tans<<'\n';
return;
}
}
int main(){
ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
cin>>K>>N;
if(K == 1)S1::GO();
else S2::GO();
}
