#include <bits/stdc++.h>
using namespace std;
#define all(c) (c).begin(),(c).end()
#define rrep(i,n) for(int i=(int)(n)-1;i>=0;i--)
#define REP(i,m,n) for(int i=(int)(m);i<(int)(n);i++)
#define rep(i,n) REP(i,0,n)
#define iter(c) __typeof((c).begin())
#define tr(it,c) for(iter(c) it=(c).begin();it!=(c).end();it++)
#define pb(a) push_back(a)
#define rd(a) cin>>(a)
#define RD(a,b) cin>>(a)>>(b)
#define pr(a) cout<<(a)<<endl
#define PR(a,b) cout<<(a)<<" "<<(b)<<endl
#define F first
#define S second
#define ll long long
bool check(int n,int m,int x,int y){return (x<0||x>=n||y<0||y>=m)?false:true;}
const ll MAX=1000000007,MAXL=1LL<<60,dx[4]={-1,0,1,0},dy[4]={0,-1,0,1};
typedef pair<int,int> P;

int n,m,k;
vector<int> v[100];
ll dp[100][20];

ll dfs(int now,int t,ll p) {
  if(t==k) {
    if(p&(1LL<<now)) return 0;
    else return (1LL<<(now-1))-1;
  }
  //if(dp[now][t]) return dp[now][t];
  ll ans=0;
  rep(i,v[now].size()) {
    ans=max(ans,dfs(v[now][i],t+1,p|(1LL<<now)));
  }
  dp[now][t]=ans;
  if(!(p&(1LL<<now))) dp[now][t]+=(1LL<<(now-1))-1;
  return dp[now][t];
}
int main() {
  cin >> n >> m >> k;
  rep(i,m) {
    int x,y;
    RD(x,y);
    v[x].pb(y);
    v[y].pb(x);
  }
  memset(dp,0,sizeof(dp));
  pr(dfs(1,0,0));
  return 0;
}