#[allow(unused_imports)]
use proconio::{
    input, fastout,
    marker::{Bytes, Chars, Usize1},
};

fn main() {
    input!{
		n: usize, _m: usize, k: i32,
		ed: [(Usize1, Usize1); _m]
    }
	let mut d = vec![vec![k+1; n]; n];
	for i in 0..n {
		d[i][i] = 0;
	}
	for &(u, v) in &ed {
		d[u][v] = 1;
		d[v][u] = 1;
	}
	for v in 0..n {
		for u in 0..n {
			for w in 0..n {
				d[u][w] = std::cmp::min(d[u][w], d[u][v] + d[v][w]);
			}
		}
	}
	let mut vis = Vec::new();
	for i in (1..n).rev() {
		vis.push(i);
		let m = vis.len();
		let mut dp = vec![vec![k+1; m]; 1<<m];
		for j in 0..m {
			dp[1<<j][j] = d[0][vis[j]];
		}
		for bit in 1..1<<m {
			for j in 0..m {
				if bit & (1 << j) == 0 { continue; }
				if dp[bit][j] > k { continue; }
				for jj in 0..m {
					if bit & (1 << jj) == 0 {
						dp[bit | 1 << jj][jj] = std::cmp::min(
							dp[bit | 1 << jj][jj], dp[bit][j] + d[vis[j]][vis[jj]]
						);
					}
				}
			}
		}
		let goal = (1 << m) - 1;
		if (0..m).all(|j| dp[goal][j] > k) {
			vis.pop();
		}
	}
    println!("{}", vis.iter().map(|i| (1i64 << i) - 1).sum::<i64>());
}