#include <bits/stdc++.h>
using namespace std;
const int N = 100005;
int m, n;
long long res;
long long f[2][N];
pair<int, int> a[N];
vector< pair<int, int> > vec;
struct SegmentTree {
pair<int, long long> T[4 * 2 * N];
void init() {
for (int i = 0; i < 4 * 2 * N; ++i) T[i] = {0, 0};
}
#define mid ((l + r) >> 1)
void upd(int i, int l, int r, int p) {
if (l == r) {
T[i] = {1, vec[l].first}; return;
}
if (mid >= p) upd(i << 1, l, mid, p);
else upd(i << 1 | 1, mid + 1, r, p);
T[i] = {T[i << 1].first + T[i << 1 | 1].first, T[i << 1].second + T[i << 1 | 1].second};
}
int find(int i, int l, int r, int k) {
if (l == r) return l;
if (k <= T[i << 1].first) return find(i << 1, l, mid, k);
return find(i << 1 | 1, mid + 1, r, k - T[i << 1].first);
}
long long get(int i, int l, int r, int L, int R) {
if (L > r || l > R) return 0;
if (L <= l && r <= R) return T[i].second;
return get(i << 1, l, mid, L, R) + get(i << 1 | 1, mid + 1, r, L, R);
}
#undef mid
} IT;
int main() {
ios::sync_with_stdio(false);
cin >> m >> n;
int cnt = 0;
for (int i = 1; i <= n; ++i) {
char x, y;
++cnt;
cin >> x >> a[cnt].first >> y >> a[cnt].second;
if (a[cnt].first > a[cnt].second) {
swap(a[cnt].first, a[cnt].second);
}
if (x == y) res += a[cnt].second - a[cnt].first, cnt--;
}
n = cnt;
sort(a + 1, a + 1 + n, [&] (pair<int, int> x, pair<int, int> y) {
return x.first + x.second < y.first + y.second;
});
for (int i = 1; i <= n; ++i) {
vec.push_back({a[i].first, i * 2}), vec.push_back({a[i].second, i * 2 + 1});
}
sort(vec.begin(), vec.end());
for (int i = 1; i <= n; ++i) {
a[i].first = lower_bound(vec.begin(), vec.end(), make_pair(a[i].first, i * 2)) - vec.begin();
a[i].second = lower_bound(vec.begin(), vec.end(), make_pair(a[i].second, i * 2 + 1)) - vec.begin();
}
IT.init();
for (int i = 1; i <= n; ++i) {
IT.upd(1, 0, n * 2 - 1, a[i].first);
IT.upd(1, 0, n * 2 - 1, a[i].second);
int p = IT.find(1, 0, n * 2 - 1, i);
f[0][i] = IT.get(1, 0, n * 2 - 1, p + 1, n * 2 - 1) - IT.get(1, 0, n * 2 - 1, 0, p);
}
IT.init();
for (int i = n; i >= 1; --i) {
IT.upd(1, 0, n * 2 - 1, a[i].first);
IT.upd(1, 0, n * 2 - 1, a[i].second);
int p = IT.find(1, 0, n * 2 - 1, n - i + 1);
f[1][i] = IT.get(1, 0, n * 2 - 1, p + 1, n * 2 - 1) - IT.get(1, 0, n * 2 - 1, 0, p);
}
if (m == 1) cout << f[0][n] + res + n;
else {
long long mn = 1e18;
for (int i = 0; i <= n; ++i) mn = min(mn, f[0][i] + f[1][i + 1]);
cout << mn + res + n;
}
}
