// 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;
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)});
}
}
int oK (int v)
{
int s = 0;
for (auto [a,b] : q)
{
if (v > b) s += v-a + v-b + 1;
else if (v < a) s += a-v + b-v + 1;
else s += b-a+1;
}
return s;
}
void Ternary_Search ()
{
int l=0 , r=1e9;
while (r-l > 2)
{
int o = (r-l) / 3;
int v1 = l+o , v2 = l+2*o;
int q1 = oK(v1) , q2 = oK(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 , oK(i));
out += mn;
}
void ouT ()
{
cout << out << '\n';
}
signed main()
{
ios::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
iN();
Ternary_Search();
ouT();
}
