#include <iostream>#include <cmath>#include <cassert>#include <vector>#include <map>#include <string>#include <cstdio>#include <cstring>#include <algorithm>using namespace std;const int MAXN = 111;const double EPS = 1e-8;int N;map<string, int> name;vector<string> g[111];vector<int> adj[111];char str[1111], s[20];double f[MAXN][MAXN];inline int sgn(double x) {if (fabs(x)<EPS) return 0;return x>0?1:-1;}inline bool sym(char c) {if (c==' ') return 1;if (c==':') return 1;if (c==',') return 1;if (c=='.') return 1;if (c=='!') return 1;if (c=='?') return 1;return 0;}int gauss(int N, int M, double a[][MAXN]) {int i, j, r, c, pvt;double maxp;for (r=0, c=0; r<N && c<M; ++r, ++c) {for (maxp=0, i=r; i < N; ++i)if (fabs(a[i][c])>fabs(maxp)) maxp = a[pvt=i][c];if (sgn(maxp)==0) {r--;continue;}if (pvt != r)for (j = r; j <= M; ++j) swap(a[r][j], a[pvt][j]);for (j = c+1; j <= M; ++j) {a[r][j] /= maxp;for (i = r+1; i < N; ++i)a[i][j] -= a[i][c]*a[r][j];}}for (i = r; i < N; ++i)if (sgn(a[i][M])) return -1;if (r < M) return M-r;for (i = M-1; i >= 0; --i)for (j = i+1; j < M; ++j)a[i][M] -= a[j][M]*a[i][j];return 0;}int main() {int i, j, k;while (cin>>N) {getchar();name.clear();for (i = 0; i < N; ++i) {g[i].clear();adj[i].clear();}for (i = 0; i < N; ++i) {gets(str);for (j = 0; j < strlen(str); ++j)if (sym(str[j])) str[j] = ' ';int off = 0;sscanf(str, "%s", s);off = strstr(str+off, s)-str;off += strlen(s);name[string(s)] = i;while (sscanf(str+off, "%s", s)==1) {off = strstr(str+off, s)-str;off += strlen(s);g[i].push_back(string(s));}}for (i = 0; i < N; ++i) {for (j = 0; j < g[i].size(); ++j) {if (name.find(g[i][j])==name.end()) continue;if (name[g[i][j]]==i) continue;adj[i].push_back(name[g[i][j]]);}}memset(f, 0, sizeof f);for (i = 0; i < N; ++i) {f[i][i] = 1;f[i][N] = 1;int len = adj[i].size();for (j = 0; j < len; ++j)f[i][adj[i][j]] -= 1.0/len;}int res = gauss(N, N, f);assert(res<1);if (res==-1) puts("Infinity");else printf("%.3fn", f[0][N]);}return 0;}
