// mrrrow mnyaa ;3c
// go play vivid/stasis! it's a really awesome free game on steam
int links[1502][1502][2];
int num_edges[1502];
int min_num_edges;
bool used[1502];
int n, call_num;
void initialize(int N) {
n = N;
call_num = 0;
min_num_edges = n - 1;
for (int i = 1; i <= n; i++) {
links[i][0][1] = 1;
for (int j = 0; j < n; j++) {
links[i][j + 1][0] = j;
links[i][j + 1][1] = j + 2;
}
links[i][n + 1][1] = -1;
num_edges[i] = n - 1;
}
}
bool dfs(int i, int j, int mi, int ma) {
used[i] = true;
for (int it = links[i][0][1]; it <= ma && links[i][it][1] != -1; it = links[i][it][1])
if (it >= mi && it == j || !used[it] && dfs(it, j, mi, ma)) return true;
return false;
}
int hasEdge(int u, int v) {
call_num++;
u++, v++;
int up = links[u][v][0], un = links[u][v][1];
int vp = links[v][u][0], vn = links[v][u][1];
links[u][up][1] = un;
links[u][un][0] = up;
links[v][vp][1] = vn;
links[v][vn][0] = vp;
num_edges[u]--;
num_edges[v]--;
int min_of = num_edges[u] < num_edges[v] ? num_edges[u] : num_edges[v];
if (call_num < n - 1) {
min_num_edges = min_of < min_num_edges ? min_of : min_num_edges;
return false;
}
if (n > 80) {
if (min_num_edges > 1) {
min_num_edges = min_of < min_num_edges ? min_of : min_num_edges;
return false;
}
}
for (int i = 1; i <= n; i++) used[i] = false;
int r = 0xffff;
while (u & r > 0 && v | ~r < n) {
if (dfs(u, v, u & r, v & ~r)) {
min_num_edges = min_of < min_num_edges ? min_of : min_num_edges;
return false;
}
r <<= 1;
}
if (!dfs(u, v, 0, n)) {
links[u][up][1] = v;
links[u][un][0] = v;
links[v][vp][1] = u;
links[v][vn][0] = u;
num_edges[u]++;
num_edges[v]++;
min_of++;
min_num_edges = min_of < min_num_edges ? min_of : min_num_edges;
return true;
} else {
min_num_edges = min_of < min_num_edges ? min_of : min_num_edges;
return false;
}
}
