#include <iostream>#include <cstdio>#include <cstdlib>#include <cstring>using namespace std;#define maxn 305struct Edge{ int v, next;} edge[maxn * 7 * 12];int n, m;int head[maxn];int xM[maxn], yM[maxn];bool chk[maxn];int count;void addedge(int a, int b){ edge[count].next = head[a]; edge[count].v = b; head[a] = count; count++;}void input(){ int t; for (int i = 0; i < n; i++) { scanf("%d", &t); for (int j = 0; j < t; j++) { int p, q; scanf("%d%d", &p, &q); addedge(i, (p - 1) * 12 + q); } }}bool SearchPath(int u){ for (int i = head[u]; i != -1; i = edge[i].next) { int v = edge[i].v; if (!chk[v]) { chk[v] = true; if (yM[v] == -1 || SearchPath(yM[v])) { yM[v] = u; xM[u] = v; return true; } } } return false;}int MaxMatch(){ int u, ret = 0; memset(xM, -1, sizeof(xM)); memset(yM, -1, sizeof(yM)); for (u = 0; u < n; u++) if (xM[u] == -1) { memset(chk, false, sizeof(chk)); if (SearchPath(u)) ret++; } return ret;}int main(){ while (scanf("%d", &n) != EOF) { count = 0; memset(head, -1, sizeof(head)); m = 7 * 12 + 1; input(); printf("%dn", MaxMatch()); } return 0;}
