#line 2 "/Users/kaage/Desktop/ProgrammingWorkspace/library/other/template.hpp"
#define _CRT_SECURE_NO_WARNINGS
#pragma target("avx2")
#pragma optimize("O3")
#pragma optimize("unroll-loops")
#include <algorithm>
#include <bitset>
#include <cassert>
#include <cfloat>
#include <climits>
#include <cmath>
#include <complex>
#include <ctime>
#include <deque>
#include <fstream>
#include <functional>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <list>
#include <map>
#include <memory>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <string.h>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
#define rep(i,n) for(int i=0;i<(n);i++)
#define REP(i,n) for(int i=1;i<=(n);i++)
#define all(V) V.begin(),V.end()
typedef long long lint;
typedef unsigned long long ulint;
typedef std::pair<int, int> P;
typedef std::pair<lint, lint> LP;
constexpr int INF = INT_MAX/2;
constexpr lint LINF = LLONG_MAX/2;
constexpr double eps = DBL_EPSILON;
constexpr double PI=3.141592653589793238462643383279;
template<class T>
class prique :public std::priority_queue<T, std::vector<T>, std::greater<T>> {};
template <class T, class U>
inline bool chmax(T& lhs, const U& rhs) {
if (lhs < rhs) {
lhs = rhs;
return 1;
}
return 0;
}
template <class T, class U>
inline bool chmin(T& lhs, const U& rhs) {
if (lhs > rhs) {
lhs = rhs;
return 1;
}
return 0;
}
inline lint gcd(lint a, lint b) {
while (b) {
lint c = a;
a = b; b = c % b;
}
return a;
}
inline lint lcm(lint a, lint b) {
return a / gcd(a, b) * b;
}
bool isprime(lint n) {
if (n == 1)return false;
for (int i = 2; i * i <= n; i++) {
if (n % i == 0)return false;
}
return true;
}
template<typename T>
T mypow(T a, lint b) {
T res(1);
while(b){
if(b&1)res*=a;
a*=a;
b>>=1;
}
return res;
}
lint modpow(lint a, lint b, lint m) {
lint res(1);
while(b){
if(b&1){
res*=a;res%=m;
}
a*=a;a%=m;
b>>=1;
}
return res;
}
template<typename T>
void printArray(std::vector<T>& vec) {
rep(i, vec.size()){
std::cout << vec[i];
std::cout<<(i==(int)vec.size()-1?"\n":" ");
}
}
template<typename T>
void printArray(T l, T r) {
T rprev = std::prev(r);
for (T i = l; i != rprev; i++) {
std::cout << *i << " ";
}
std::cout << *rprev << std::endl;
}
LP extGcd(lint a,lint b) {
if(b==0)return {1,0};
LP s=extGcd(b,a%b);
std::swap(s.first,s.second);
s.second-=a/b*s.first;
return s;
}
LP ChineseRem(const lint& b1,const lint& m1,const lint& b2,const lint& m2) {
lint p=extGcd(m1,m2).first;
lint tmp=(b2-b1)*p%m2;
lint r=(b1+m1*tmp+m1*m2)%(m1*m2);
return std::make_pair(r,m1*m2);
}
/*template<typename F>
inline constexpr decltype(auto) lambda_fix(F&& f){
return [f=std::forward<F>(f)](auto&&... args){
return f(f,std::forward<decltype(args)>(args)...);
};
}*/
#line 2 "main.cpp"
int n,k;
std::vector<P> vec;
lint check(int x,int y){
lint res=0;
for(const P& i:vec){
int a=std::abs(i.first-x)+1+std::abs(x-i.second);
int b=std::abs(i.first-y)+1+std::abs(y-i.second);
res+=std::min(a,b);
}
return res;
}
int main(){
std::cin>>k>>n;
lint ans=0;
rep(i,n){
char p,q;
int s,t;
std::cin>>p>>s>>q>>t;
if(p!=q){
if(s>t)std::swap(s,t);
vec.emplace_back(s,t);
}
else ans+=std::abs(s-t);
}
if(vec.empty()){
std::cout<<ans<<std::endl;
return 0;
}
if(k==1){
std::vector<int> vec2;
for(const P& i:vec){
vec2.emplace_back(i.first);
vec2.emplace_back(i.second);
}
std::sort(all(vec2));
int x=vec2[vec2.size()/2];
for(const P& i:vec){
ans+=std::abs(i.first-x)+1+std::abs(x-i.second);
}
std::cout<<ans<<std::endl;
}
else{
std::vector<int> vec2;
for(const P& i:vec){
vec2.emplace_back(i.first);
vec2.emplace_back(i.second);
}
std::sort(all(vec2));
lint cnt=LINF;
rep(i,vec2.size()){
int min=-1,max=1000000001;
while(min+2<max){
int mid=(min+max)/2;
if(check(vec2[i],mid)<=check(vec2[i],mid+1))max=mid+1;
else min=mid;
}
chmin(cnt,check(vec2[i],min));
chmin(cnt,check(vec2[i],min+1));
chmin(cnt,check(vec2[i],max));
}
std::cout<<ans+cnt<<std::endl;
}
}
