#include<iostream>#include<algorithm>#include<cstdio>#include<cstring>#include<cstdlib>#include<cmath>using namespace std;int s[15];double cost[15];double ans;int n,m;void dfs(int depth, int state, double t){ if(t<ans) return; if(depth==n){ if(state+1==(1<<n)) ans=t; return; } dfs(depth+1,state,t); dfs(depth+1,state^s[depth],t*cost[depth]);}int main(){while(scanf("%d%d",&n,&m)!=EOF){if(n==0 && m==0)break;ans=-1;for(int i=0;i<n;i++){int k;scanf("%d",&k);s[i]=(1<<i); while(k--){ int p; scanf("%d",&p); s[i]=s[i]|(1<<(--p)); } int t;scanf("%d",&t);cost[i]=1-1.0*t/100;}dfs(0,0,m); if(ans>0) printf("%.2lfn",ans); else printf("-1n");}return 0;}
