#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define NU 30000
#define NV 2000
int min(int a, int b) { return a < b ? a : b; }
int max(int a, int b) { return a > b ? a : b; }
int nu, nv;
int *eu[NV], eo[NV];
void append(int v, int u) {
int o = eo[v]++;
if (o >= 2 && (o & o - 1) == 0)
eu[v] = (int *) realloc(eu[v], o * 2 * sizeof *eu[v]);
eu[v][o] = u;
}
int l, u_;
int uu[NV], vv[NU], pp[NU]; char visited[NV];
void dfs(int v) {
int o, o_;
visited[v] = 1;
for (o = 0, o_ = 0; o < eo[v]; o++) {
int u = eu[v][o], w = vv[u];
if (u <= l)
continue;
eu[v][o_++] = u;
if (w == -1 || !visited[w]) {
pp[u] = v;
if (w == -1)
u_ = min(u_, u);
else
dfs(w);
}
}
eo[v] = o_;
}
int main() {
int m, u, v, v_, r, ans;
scanf("%d%d%d", &nu, &nv, &m);
for (v = 0; v < nv; v++)
eu[v] = (int *) malloc(2 * sizeof *eu[v]);
while (m--) {
scanf("%d%d", &u, &v), u--, v--;
append(v, u);
}
memset(uu, -1, nv * sizeof *uu), memset(vv, -1, nu * sizeof *vv);
for (v = 0; v < nv; v++) {
memset(visited, 0, nv * sizeof *visited);
l = -1, u_ = nu, dfs(v);
u = u_;
while (1) {
v_ = pp[u], u_ = uu[v_];
uu[v_] = u, vv[u] = v_;
u = u_;
if (v_ == v)
break;
}
}
r = -1;
for (v = 0; v < nv; v++)
r = max(r, uu[v]);
ans = 0;
for (u = 0; u < nu; u++) {
ans += nu - r;
if ((v = vv[u]) != -1) {
memset(visited, 0, nv * sizeof *visited);
l = u, u_ = nu, dfs(v);
if (u_ == nu)
break;
r = max(r, u_);
u = u_;
while (1) {
v_ = pp[u], u_ = uu[v_];
uu[v_] = u, vv[u] = v_;
u = u_;
if (v_ == v)
break;
}
vv[u] = -1;
}
}
printf("%d\n", ans);
return 0;
}
