#include <cmath>#include <cstdio>using namespace std;inline double sqr(const double x){ return x * x;}double x[1001], y[1001], r[1001];bool mp[1024][1024];void bfs(int n, int s){ static bool m[1024]; static int p, t, q[1024]; for (int i = 0; i < n; i++) m[i] = false; m[s] = true; q[0] = s; p = 0; t = 1; while(p < t) { for (int i = 0; i < n; i++) if(!m[i] && mp[q[p]][i]) { m[i] = true; q[t++] = i; } ++p; } for (int i = 0; i < n; i++) if(m[i]) mp[s][i] = mp[i][s] = true;}int main(void){ int n; double a, b; while(scanf("%d", &n) != EOF) { for (int i = 0; i <= n + 1; i++) for (int j = 0; j <= n + 1; j++) mp[i][j] = false; for (int i = 0; i < n; i++) { scanf("%lf%lf%lf", &x[i], &y[i], &r[i]); if(y[i] - r[i] < 0) mp[i][n] = mp[n][i] = true; if(y[i] + r[i] > 1000) mp[i][n + 1] = mp[n + 1][i] = true; for (int j = 0; j < i; j++) if (sqr(x[i] - x[j]) + sqr(y[i] - y[j]) < sqr(r[i] + r[j])) mp[i][j] = mp[j][i] = true; } if(mp[n][n + 1]) { printf("Bill will be bitten.n"); continue; } bfs(n + 2, n + 1); if(mp[n][n + 1]) { printf("Bill will be bitten.n"); continue; } a = b = 1000.0; for (int i = 0; i < n; i++) { if(!mp[i][n + 1]) continue; if(x[i] - r[i] < 0) { a = a < y[i] - sqrt(sqr(r[i]) - sqr(x[i])) ? a : y[i] - sqrt(sqr(r[i]) - sqr(x[i])); } if(x[i] + r[i] > 1000) { b = b < y[i] - sqrt(sqr(r[i]) - sqr(1000 - x[i])) ? b : y[i] - sqrt(sqr(r[i]) - sqr(1000 - x[i])); } } printf("Bill enters at (0.00, %.2lf) and leaves at (1000.00, %.2lf).n", a, b); }}
