#include "prg.h"
#include<bits/stdc++.h>
using namespace std;
int fa[1005];
int findfather(int x){
	return x==fa[x]?x:fa[x]=findfather(fa[x]);
}
vector<pair<int,int>>g[1005];
int dj[3005],dist[1005];
void dfs(int x,int la){
	for(auto pi:g[x]){
		int cu=pi.first,c2=pi.second;
		if(cu==la)continue;
		dist[cu]=dist[x]^dj[c2];
		dfs(cu,x);
	}
}
int dep[1005],af[21][1005];
void dfss(int x,int la){
	for(auto pi:g[x]){
		int cu=pi.first;
		if(cu==la)continue;
		dep[cu]=dep[x]+1;af[0][cu]=x;
		dfss(cu,x);
	}
}
int lca(int x,int y){
	if(dep[x]<dep[y])swap(x,y);
	for(int i=9;i>=0;--i)if(dep[x]-dep[y]>=(1<<i))x=af[i][x];
	if(x==y)return x;
	for(int i=9;i>=0;--i)if(af[i][x]!=af[i][y])x=af[i][x],y=af[i][y];
	return af[0][x];
}
int suan(int u,int v){
	int l=lca(u,v);
	return dep[u]+dep[v]-2*dep[l];
}
int solve(int n,int m,int k,vector<int>op,array<vector<int>,3000>x,int c,array<array<int,3000>,25>s){
	if(k==2){
		int a1=0,a2=0;
		for(int i=0;i<c;++i){
			int h=0;
			for(int j=0;j<m;++j){
				h+=s[i][j];
			}
			if(h>=(m/4+m/2)/2&&h<=(m*3/4+m/2)/2)++a1;
			else ++a2;
		}
		return (a2<=1?1:2);
	}
	if(op[k-2]!=2){
		int a1=0,a2=0;
		for(int i=0;i<c;++i){
			int h=0;
			for(int j=0;j<m;++j){
				h+=s[i][j];
			}
			if(h>=m/2-m/16&&h<=m/2+m/16)++a1;
			else ++a2;
		}
		return (a2<=1?1:2);
	}
	if(op[k-3]!=2){
		vector<vector<int>>gs(n);
		for(int i=0;i<m;++i){
			gs[x[i][k-1]].emplace_back(i);
		}
		int mn=0,ms=0;
		for(int i=0;i<n;++i)if((signed)gs[i].size()>=2){
			int t=gs[i].size(),kn=0;
			for(int j=0;j<c;++j){
				int h=0;
				for(auto k:gs[i]){
					h+=s[j][k];
				}
				if(h==0||h==t)++kn;
			}
			mn+=kn;++ms;
		}
		if(1.0*mn/ms>6.7)return 2;
		return 1;
	}
	if(op[0]==1){
		for(int i=0;i<c;++i){
			for(int j=0;j<m;++j){
				s[i][j]^=1;
			}
		}
	}
	int he=0,gs=0;
	int TT=100;
	mt19937 mt(13770618);
	while(TT--){
		vector<int>ok(m),p(m);
		for(int i=0;i<n;++i)fa[i]=i,g[i].clear();
		for(int i=0;i<m;++i)p[i]=i;
		shuffle(p.begin(),p.end(),mt);
		for(int ii=0;ii<m;++ii){
			int i=p[ii];
			int u=x[i][2],v=x[i][3];
			int fu=findfather(u),fv=findfather(v);
			if(fu!=fv){
				fa[fu]=fv;
				g[u].emplace_back(v,i);
				g[v].emplace_back(u,i);
			}else{
				ok[i]=1;
			}
		}
		dep[0]=0;af[0][0]=af[0][n]=n;dfss(0,-1);
		for(int i=1;i<=10;++i)for(int j=0;j<=n;++j)
			af[i][j]=af[i-1][af[i-1][j]];
		for(int i=0;i<m;++i){
			if(ok[i]&&suan(x[i][2],x[i][3])>2)ok[i]=0;
		}
		for(int t=0;t<c;++t){
			for(int i=0;i<m;++i){
				dj[i]=s[t][i];
			}
			dfs(0,-1);
			for(int i=0;i<m;++i)if(ok[i]){
				int u=x[i][2],v=x[i][3];
				he+=dj[i]^dist[u]^dist[v];++gs;
			}
		}
	}
	printf("%.10f\n",1.0*he/gs);
	if(1.0*he/gs<0.452)return 2;
	return 1;
}