#include <bits/stdc++.h>
using namespace std;
int k, n;
vector <int> h, w, hw;
int movementI, movementJ;
long long check(int i, int j){
if(i>=n<<1||j>=n<<1||i<0||j<0)return 200000000000000;
long long tot=0;
movementI=0, movementJ=0;
int throughI, throughJ;
for(int k = 0;k < n;k ++){
throughI=abs(h[k]-hw[i])+abs(w[k]-hw[i]);
throughJ=abs(h[k]-hw[j])+abs(w[k]-hw[j]);
if(throughI<throughJ){
if(hw[i]<h[k])
movementI++;
if(hw[i]>w[k])
movementI--;
tot+=throughI;
}else{
if(hw[j]<h[k])
movementJ++;
if(hw[j]>w[k])
movementJ--;
tot+=throughJ;
}
}
return tot;
}
int main(){
scanf("%d %d", &k, &n);
bool cross;int s, t;
long long tot1=0;
char c;
while(n--){
while(true){
c=getchar();
if(c=='A'){
cross=false;
break;
}else if(c=='B'){
cross=true;
break;
}
}
scanf("%d", &s);
while(true){
c=getchar();
if(c=='A'){
break;
}else if(c=='B'){
cross^=true;
break;
}
}
scanf("%d", &t);
if(cross){
if(s>t)
swap(s, t);
h.push_back(s);
w.push_back(t);
hw.push_back(s);
hw.push_back(t);
tot1++;
}else{
tot1+=abs(t-s);
}
}
n=h.size();
if(k==1){
sort(hw.begin(), hw.end());
n=hw.size();
long long tot2=0;
k=n>>1;
for(int i = 0;i < n;i ++)
tot2+=abs(hw[k]-hw[i]);
printf("%lld\n", tot1+tot2);
}else if(k==2){
long long tot2=200000000000000;
long long curtot;
long long up, down, left, right, minall;
int i=(n<<1)/3, j=(n<<2)/3;
for(int l = 0;l < 400;l ++){
curtot=check(i, j);
i+=movementI;
j+=movementJ;
tot2=min(tot2, curtot);
}
for(int l = 0;l < 400;l ++){
curtot=check(i, j);
if(l&1)
i+=movementI;
else
j+=movementJ;
tot2=min(tot2, curtot);
}
while(true){
curtot=check(i, j);
up=check(i, j+1);
down=check(i, j-1);
left=check(i-1, j);
right=check(i+1, j);
minall=min(curtot, min(up, min(down, min(left, right))));
tot2=min(tot2, minall);
if(curtot==minall)
break;
if(up==minall)
j++;
if(down==minall)
j--;
if(left==minall)
i--;
if(right==minall)
i++;
}
printf("%lld\n", tot1+tot2);
}
return 0;
}
/*
2 5
B 0 A 4
B 1 B 3
A 5 B 7
B 2 A 6
B 1 A 7
*/
