#include <bits/stdc++.h>
using namespace std;
int const MAX=1e5+5;
int k,n;
long long rasp;
struct interval{
int st,dr,mij;
bool operator<(interval ot){
return mij<ot.mij;
}
}intv[MAX];
int total;
vector<int>poz;
void read(){
cin>>k>>n;
int i;
for(i=1;i<=n;++i){
char tip1,tip2;
int poz1,poz2;
cin>>tip1>>poz1>>tip2>>poz2;
if(tip1==tip2)
rasp+=abs(poz1-poz2);
else{
++rasp;
if(poz1>poz2)
swap(poz1,poz2);
intv[++total]={poz1,poz2,poz1+poz2};
}
}
sort(intv+1,intv+total+1);
}
long long solve1(){
int i;
for(i=1;i<=total;++i){
poz.push_back(intv[i].st);
poz.push_back(intv[i].dr);
}
sort(poz.begin(),poz.end());
int median=poz.size()/2;
long long sum=0;
for(i=0;i<(int)poz.size();++i)
sum+=abs(poz[median]-poz[i]);
return sum;
}
multiset<int>small1,big1,small2,big2;
long long const INF=1e18;
long long ss1,sb1,ss2,sb2;
void minself(long long& x,long long val){
if(x>val)
x=val;
}
void add(multiset<int>&small,multiset<int>&big,long long& ss,long long& sb,int val1,int val2){
small.insert(val1);
ss+=val1;
small.insert(val2);
ss+=val2;
int nr=*small.rbegin();
small.erase(small.find(nr));
ss-=nr;
big.insert(nr);
sb+=nr;
}
void del(multiset<int>&small,multiset<int>&big,long long& ss,long long& sb,int val1,int val2){
if(small.find(val1)!=small.end()){
small.erase(small.find(val1));
ss-=val1;
}
else{
big.erase(big.find(val1));
sb-=val1;
}
if(small.find(val2)!=small.end()){
small.erase(small.find(val2));
ss-=val2;
}
else{
big.erase(big.find(val2));
sb-=val2;
}
if(small.size()<big.size()){
int nr=*big.begin();
big.erase(big.find(nr));
sb-=nr;
small.insert(nr);
ss+=nr;
}
if(small.size()>big.size()){
int nr=*small.rbegin();
small.erase(small.find(nr));
ss-=nr;
big.insert(nr);
sb+=nr;
}
}
long long solve2(){
long long minim=INF;
int i;
for(i=1;i<=total;++i)
add(small2,big2,ss2,sb2,intv[i].st,intv[i].dr);
for(i=1;i<total;++i){
del(small2,big2,ss2,sb2,intv[i].st,intv[i].dr);
add(small1,big1,ss1,sb1,intv[i].st,intv[i].dr);
minself(minim,sb1-ss1+sb2-ss2);
}
return minim;
}
int main(){
read();
if(k==1)
cout<<rasp+solve1();
else
cout<<rasp+min(solve1(),solve2());
return 0;
}
