#include <stdio.h>
#define N 100000
#define INF 0x3f3f3f3f
long long min(long long a, long long b) { return a < b ? a : b; }
unsigned int X = 12345;
int rand_() {
return (X *= 3) >> 1;
}
int *aa;
void sort(int *ii, int l, int r) {
while (l < r) {
int i = l, j = l, k = r, i_ = ii[l + rand_() % (r - l)], tmp;
while (j < k)
if (aa[ii[j]] == aa[i_])
j++;
else if (aa[ii[j]] < aa[i_]) {
tmp = ii[i], ii[i] = ii[j], ii[j] = tmp;
i++, j++;
} else {
k--;
tmp = ii[j], ii[j] = ii[k], ii[k] = tmp;
}
sort(ii, l, i);
l = k;
}
}
int xx[N * 2];
int zz[1 + N * 2], ll[1 + N * 2], rr[1 + N * 2], ii[1 + N * 2], kk[1 + N * 2], _, u_, l_, r_; long long sum[1 + N * 2];
int node(int i) {
zz[_] = rand_(), ll[_] = rr[_] = 0;
ii[_] = i, kk[_] = 1, sum[_] = xx[i];
return _++;
}
void pul(int u) {
int l = ll[u], r = rr[u];
kk[u] = 1 + kk[l] + kk[r];
sum[u] = xx[ii[u]] + sum[l] + sum[r];
}
void split(int u, int i) {
int c;
if (u == 0) {
l_ = r_ = 0;
return;
}
c = xx[ii[u]] != xx[i] ? xx[ii[u]] - xx[i] : ii[u] - i;
if (c < 0) {
split(rr[u], i);
rr[u] = l_, l_ = u;
} else {
split(ll[u], i);
ll[u] = r_, r_ = u;
}
pul(u);
}
int merge(int u, int v) {
if (u == 0)
return v;
if (v == 0)
return u;
if (zz[u] < zz[v]) {
rr[u] = merge(rr[u], v), pul(u);
return u;
} else {
ll[v] = merge(u, ll[v]), pul(v);
return v;
}
}
long long query(int k) {
int u;
long long x;
u = u_, x = 0;
while (u) {
int l = ll[u];
if (k <= kk[l])
u = l;
else {
k -= kk[l] + 1, x += sum[l] + xx[ii[u]];
u = rr[u];
}
}
return x;
}
void tr_add(int i) {
split(u_, i);
u_ = merge(merge(l_, node(i)), r_);
}
int main() {
static int ii[N * 2], xx_[N];
static long long pp[N + 1], qq[N + 1];
int k, n, n_, i;
long long ans, mn;
scanf("%d%d", &k, &n);
ans = 0, n_ = 0;
for (i = 0; i < n; i++) {
static char s[2], t[2];
int l, r, tmp;
scanf("%s%d%s%d", s, &l, t, &r);
if (l > r)
tmp = l, l = r, r = tmp;
if (s[0] == t[0]) {
ans += r - l;
continue;
}
xx[n_ << 1 | 0] = l, xx[n_ << 1 | 1] = r, n_++;
}
n = n_;
ans += n;
if (k == 1) {
for (i = 0; i < n * 2; i++)
ii[i] = i;
aa = xx, sort(ii, 0, n * 2);
for (i = 0; i < n * 2; i++)
ans += xx[ii[i]] * (i < n ? -1 : 1);
} else {
for (i = 0; i < n; i++) {
xx_[i] = xx[i << 1 | 0] + xx[i << 1 | 1];
ii[i] = i;
}
aa = xx_, sort(ii, 0, n);
_ = 1, u_ = 0;
for (i = 0; i <= n; i++) {
pp[i] = sum[u_] - query(i) * 2;
if (i < n)
tr_add(ii[i] << 1 | 0), tr_add(ii[i] << 1 | 1);
}
_ = 1, u_ = 0;
for (i = n; i >= 0; i--) {
if (i < n)
tr_add(ii[i] << 1 | 0), tr_add(ii[i] << 1 | 1);
qq[i] = sum[u_] - query(n - i) * 2;
}
mn = INF;
for (i = 0; i <= n; i++)
mn = min(mn, pp[i] + qq[i]);
ans += mn;
}
printf("%lld\n", ans);
return 0;
}
