#pragma GCC optimize("Ofast")
#include<bits/stdc++.h>
using namespace std;
#define pb push_back
#define fi first
#define se second
#define sz(a) (int)(a.size())
#define all(a) a.begin(),a.end()
#define lb lower_bound
#define ub upper_bound
#define owo ios_base::sync_with_stdio(0);cin.tie(0);
#define INF (ll)(1e18)
#define debug(...) fprintf(stderr, __VA_ARGS__),fflush(stderr)
#define time__(d) for(long blockTime = 0; (blockTime == 0 ? (blockTime=clock()) != 0 : false);\
debug("%s time : %.4fs\n", d, (double)(clock() - blockTime) / CLOCKS_PER_SEC))
typedef long long int ll;
typedef long double ld;
typedef pair<ll,ll> PII;
typedef pair<int,int> pii;
typedef vector<vector<int>> vii;
typedef vector<vector<ll>> VII;
ll gcd(ll a,ll b){if(!b)return a;else return gcd(b,a%b);}
int main()
{
owo
int k,n;
cin>>k>>n;
vector<int>s,t;
ll ans = 0;
for(int i=0;i<n;i++){
char a,c;
int b,d;
cin>>a>>b>>c>>d;
if(a == c){ans+=abs(d-b);continue;}
s.pb(b);
t.pb(d);
}
if(k == 1){
vector<int>p;
for(int x:s)p.pb(x);
for(int x:t)p.pb(x);
if(!p.empty()){
sort(all(p));
int mid = p[sz(p)/2];
for(int i=0;i<sz(p)/2;i++)ans+=mid-p[i];
for(int i=sz(p)/2;i<sz(p);i++)ans+=p[i]-mid;
}
cout<<ans+sz(p)/2;
}
else{
n = sz(s);
ll add =0;
if(n){
vector<ll>pref(n),suff(n);
multiset<int,greater<int>>lf;
multiset<int>rg;
ll slf = 0,srg = 0;
vector<int>id(n);
for(int i=0;i<n;i++)id[i] = i;
sort(all(id),[=](int x,int y){return s[y]+t[y] > s[x]+t[x];});
for(int i=0;i<n;i++){
int a = s[id[i]];
int b = t[id[i]];
//cout<<a<<" "<<b<<'\n';
lf.insert(a);
lf.insert(b);
slf+=a;
slf+=b;
while(sz(lf)-sz(rg)>1){
rg.insert(*lf.begin());
srg+=*lf.begin();
slf-=*lf.begin();
lf.erase(lf.begin());
}
while(!lf.empty() && !rg.empty() && *lf.begin() > *rg.begin()){
int ta = *lf.begin();
int tb = *rg.begin();
slf+=tb-ta;
srg+=ta-tb;
lf.erase(lf.begin());
rg.erase(rg.begin());
lf.insert(tb);
rg.insert(ta);
}
ll mid = *lf.begin();
pref[i] = sz(lf)*mid - slf + srg - sz(rg)*mid;
}
slf = srg = 0;
lf.clear();
rg.clear();
for(int i=n-1;i>=0;i--){
int a = s[id[i]];
int b = t[id[i]];
//cout<<a<<" "<<b<<'\n';
lf.insert(a);
lf.insert(b);
slf+=a;
slf+=b;
while(sz(lf)-1 > sz(rg)){
rg.insert(*lf.begin());
srg+=*lf.begin();
slf-=*lf.begin();
lf.erase(lf.begin());
}
while(!lf.empty() && !rg.empty() && *lf.begin() > *rg.begin()){
int ta = *lf.begin();
int tb = *rg.begin();
slf+=tb-ta;
srg+=ta-tb;
lf.erase(lf.begin());
rg.erase(rg.begin());
lf.insert(tb);
rg.insert(ta);
}
ll mid = *lf.begin();
suff[i] = sz(lf)*mid - slf + srg - sz(rg)*mid;
}
add = min(pref[n-1],suff[0]);
for(int i=0;i<n-1;i++)add = min(add,pref[i]+suff[i+1]);
}
cout<<ans+add+n<<'\n';
}
}
/*
1 5
B0A4
B1B3
A5B7
B2A6
B1A7
2 5
B0A4
B1B3
A5B7
B2A6
B1A7
*/
