// Alir3za.Zar3 -> Shiraz , Iran
#include <bits/stdc++.h>
using namespace std;
#define int long long
const int N = 1e5+7 , Inf = 2e18;
int k,n , out=0 , Ol=Inf,Or;
vector<pair<int,int>> q;
void iN ()
{
cin >> k >> n;
for (int i=1; i<=n; i++)
{
char P,Q; int S,T;
cin >> P >> S >> Q >> T;
if (P == Q)
out += abs(S - T);
else
{
q.push_back({min(S,T),max(S,T)});
Or = max(Or , max(S , T));
Ol = min(Ol , min(S , T));
}
}
}
int oK (int v1 , int v2)
{
int s = 0;
for (auto [a,b] : q)
{
int k1 = 0 , k2 = 0;
if (v1 > b) k1 += v1-a + v1-b + 1;
else if (v1 < a) k1 += a-v1 + b-v1 + 1;
else k1 += b-a+1;
if (v2 > b) k2 += v2-a + v2-b + 1;
else if (v2 < a) k2 += a-v2 + b-v2 + 1;
else k2 += b-a+1;
s += min(k1 , k2);
}
return s;
}
int nxt_Ternary (int l , int r , int p)
{
while (r-l > 2)
{
int o = (r-l) / 3;
int v1 = l+o , v2 = l+2*o;
int q1 = oK(p , v1);
int q2 = oK(p , v2);
if (q1 <= q2) r=v2;
else l=v1;
}
int mn = Inf;
for (int i=l; i<=r; i++)
mn = min(mn , oK(p,i));
return mn;
}
void Ternary_Search ()
{
int l=Ol , r=Or;
while (r-l > 2)
{
int o = (r-l) / 3;
int v1 = l+o , v2 = l+2*o;
int q1 = nxt_Ternary(v1,Or,v1);
int q2 = nxt_Ternary(v2,Or,v2);
if (q1 < q2) r=v2;
else if (q1 == q2) l=v1,r=v2;
else l=v1;
}
int mn = Inf;
for (int i=l; i<=r; i++)
mn = min(mn , nxt_Ternary(i,Or,i));
out += mn;
}
void ouT ()
{
cout << out << '\n';
}
signed main()
{
ios::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
iN();
if (!q.empty())
Ternary_Search();
ouT();
}
