Problem: Niwel is a little golden bear. As everyone knows, bears live in forests, but Niwel got tired of seeing all the trees so he decided to move to the city.

In the city, Niwel took on a job managing bears to deliver goods. The city that he lives in can be represented as a directed graph with n nodes and m edges. Each edge has a weight capacity. A delivery consists of a bear carrying weights with their bear hands on a simple path from node 1 to node n. The total weight that travels across a particular edge must not exceed the weight capacity of that edge.

Niwel has exactly x bears. In the interest of fairness, no bear can rest, and the weight that each bear carries must be exactly the same. However, each bear may take different paths if they like.

Niwel would like to determine, what is the maximum amount of weight he can deliver (it's the sum of weights carried by bears). Find the maximum weight.

Input

The first line contains three integers n, m and x (2 ≤ n ≤ 50, 1 ≤ m ≤ 500, 1 ≤ x ≤ 100 000) — the number of nodes, the number of directed edges and the number of bears, respectively.

Each of the following m lines contains three integers ai, bi and ci (1 ≤ ai, bi ≤ n, ai ≠ bi, 1 ≤ ci ≤ 1 000 000). This represents a directed edge from node ai to bi with weight capacity ci. There are no self loops and no multiple edges from one city to the other city. More formally, for each i and j that i ≠ j it's guaranteed that ai ≠ aj or bi ≠ bj. It is also guaranteed that there is at least one path from node 1 to node n.

Output

Print one real value on a single line — the maximum amount of weight Niwel can deliver if he uses exactly x bears. Your answer will be considered correct if its absolute or relative error does not exceed 10 - 6.

Namely: let's assume that your answer is a, and the answer of the jury is b. The checker program will consider your answer correct if <image>.

Examples

Input

4 4 3
1 2 2
2 4 1
1 3 1
3 4 2


Output

1.5000000000


Input

5 11 23
1 2 3
2 3 4
3 4 5
4 5 6
1 3 4
2 4 5
3 5 6
1 4 2
2 5 3
1 5 2
3 2 30


Output

10.2222222222

Note

In the first sample, Niwel has three bears. Two bears can choose the path <image>, while one bear can choose the path <image>. Even though the bear that goes on the path <image> can carry one unit of weight, in the interest of fairness, he is restricted to carry 0.5 units of weight. Thus, the total weight is 1.5 units overall. Note that even though Niwel can deliver more weight with just 2 bears, he must use exactly 3 bears on this day.

Solution (in JAVA):

Solution:
import java.io.*;
import java.math.*;
import java.util.*;


public class Main {

	static int mod = (int) 1e9 + 7;
	static int MAX = (int) 1e7;

	public static void main(String[] args) {
		FasterScanner s = new FasterScanner();
		PrintWriter out = new PrintWriter(System.out);
		int n =s.nextInt();
		int m=s.nextInt();
		int x =s.nextInt();
		int[] u = new int[m];
		int[] v = new int[m];
		int[] c = new int[m];
		for(int i=0;i<m;i++){
			u[i] = s.nextInt()-1;
			v[i] = s.nextInt()-1;
			c[i] = s.nextInt();
		}
		double l = 0;
		double r = 1e8;
		double e = 1e-7/x;
		while(r-l>e){
//			out.println(r+" "+l);
			List<Edge>[] g = createGraph(n);
			double mid = (l+r)/2;
			for(int i= 0 ;i<m;i++){
				addEdge(g, u[i], v[i], (long)(c[i]/mid));
//				out.println((long)(c[i]/mid));
			}
			long flow = maxFlow(g, 0, n-1);
//			out.println(flow);
			if(flow>=x){
				l=mid;
			}
			else
				r=mid;
		}
		out.println(l*x);
		out.close();
	}
	static class Edge {
		int t, rev, f;
		long cap;
		public Edge(int t, int rev, long cap) {
			this.t = t;
			this.rev = rev;
			this.cap = cap;
		}
	}

	public static List<Edge>[] createGraph(int nodes) {
		List<Edge>[] graph = new List[nodes];
		for (int i = 0; i < nodes; i++)
			graph[i] = new ArrayList<>();
		return graph;
	}

	public static void addEdge(List<Edge>[] graph, int s, int t, long cap) {
		graph[s].add(new Edge(t, graph[t].size(), cap));
		graph[t].add(new Edge(s, graph[s].size() - 1, 0));
	}

	static boolean dinicBfs(List<Edge>[] graph, int src, int dest, int[] dist) {
		Arrays.fill(dist, -1);
		dist[src] = 0;
		int[] Q = new int[graph.length];
		int sizeQ = 0;
		Q[sizeQ++] = src;
		for (int i = 0; i < sizeQ; i++) {
			int u = Q[i];
			for (Edge e : graph[u]) {
				if (dist[e.t] < 0 && e.f < e.cap) {
					dist[e.t] = dist[u] + 1;
					Q[sizeQ++] = e.	t;
				}
			}
		}
		return dist[dest] >= 0;
	}

	static long dinicDfs(List<Edge>[] graph, int[] ptr, int[] dist, int dest, int u, long l) {
		if (u == dest)
			return l;
		for (; ptr[u] < graph[u].size(); ++ptr[u]) {
			Edge e = graph[u].get(ptr[u]);
			if (dist[e.t] == dist[u] + 1 && e.f < e.cap) {
				long df = dinicDfs(graph, ptr, dist, dest, e.t, Math.min(l, e.cap - e.f));
				if (df > 0) {
					e.f += df;
					graph[e.t].get(e.rev).f -= df;
					return df;
				}
			}
		}
		return 0;
	}

	public static long maxFlow(List<Edge>[] graph, int src, int dest) {
		long flow = 0;
		int[] dist = new int[graph.length];
		while (dinicBfs(graph, src, dest, dist)) {
			int[] ptr = new int[graph.length];
			while (true) {
				long df = dinicDfs(graph, ptr, dist, dest, src, Integer.MAX_VALUE);
				if (df == 0)
					break;
				flow += df;
			}
		}
		return flow;
	}
	
	
	
	static int ans(ArrayList<Character>[] l , char a,int n){
		if(n==1)
			return 1;
		int sum=0;
		for(int i=0;i<l[a-'a'].size();i++){
			sum+=ans(l,l[a-'a'].get(i),n-1);
		}
		return sum;
	}
	static void dfs1(List<Integer>[] graph, boolean[] used, List<Integer> order, int u) {
		used[u] = true;
		for (int v : graph[u])
			if (!used[v])
				dfs1(graph, used, order, v);
		order.add(u);
	}

	static void dfs2(List<Integer>[] reverseGraph, int[] comp, int u, int color) {
		comp[u] = color;
		for (int v : reverseGraph[u])
			if (comp[v] == -1)
				dfs2(reverseGraph, comp, v, color);
	}

	public static boolean[] solve2Sat(List<Integer>[] graph) {
		int n = graph.length;
		boolean[] used = new boolean[n];
		List<Integer> order = new ArrayList<>();
		for (int i = 0; i < n; ++i)
			if (!used[i])
				dfs1(graph, used, order, i);

		List<Integer>[] reverseGraph = new List[n];
		for (int i = 0; i < n; i++)
			reverseGraph[i] = new ArrayList<>();
		for (int i = 0; i < n; i++)
			for (int j : graph[i])
				reverseGraph[j].add(i);

		int[] comp = new int[n];
		Arrays.fill(comp, -1);
		for (int i = 0, color = 0; i < n; ++i) {
			int u = order.get(n - i - 1);
			if (comp[u] == -1)
				dfs2(reverseGraph, comp, u, color++);
		}

		for (int i = 0; i < n; ++i)
			if (comp[i] == comp[i ^ 1])
				return null;

		boolean[] res = new boolean[n / 2];
		for (int i = 0; i < n; i += 2)
			res[i / 2] = comp[i] > comp[i ^ 1];
		return res;
	}

	public static int[] createSets(int size) {
		int[] p = new int[size];
		for (int i = 0; i < size; i++)
			p[i] = i;
		return p;
	}

	public static int root(int[] p, int x) {
		return x == p[x] ? x : (p[x] = root(p, p[x]));
	}

	public static void unite(int[] p, int a, int b) {
		a = root(p, a);
		b = root(p, b);
		if (a != b)
			p[a] = b;
	}

	public static boolean nextPermutation(int[] p) {
		for (int a = p.length - 2; a >= 0; --a)
			if (p[a] < p[a + 1])
				for (int b = p.length - 1;; --b)
					if (p[b] > p[a]) {
						int t = p[a];
						p[a] = p[b];
						p[b] = t;
						for (++a, b = p.length - 1; a < b; ++a, --b) {
							t = p[a];
							p[a] = p[b];
							p[b] = t;
						}
						return true;
					}
		return false;
	}

	public static boolean isPrime(long n) {
		if (n <= 1)
			return false;
		for (long i = 2; i * i <= n; i++)
			if (n % i == 0)
				return false;
		return true;
	}

	static class SegTree {
		int[] val;
		int n;

		SegTree(int n) {
			val = new int[2 * n];
			for (int i = 0; i < n; i++)
				val[n + i] = i + 1;
			for (int i = n - 1; i >= 0; i--)
				val[i] = Math.max(val[2 * i], val[2 * i + 1]);
			this.n = n;
		}

		void upd(int p) {
			p += n;
			val[p] = -1;
			for (; (p >>= 1) != 0;) {
				val[p] = Math.max(val[2 * p], val[2 * p + 1]);
			}
		}

		int query(int l, int r) { // sum on interval [l, r)
			// System.out.println(l+" "+r);
			int res = -1;
			for (l += n, r += n; l < r; l >>= 1, r >>= 1) {
				if ((l & 1) != 0)
					res = Math.max(res, val[l++]);
				if ((r & 1) != 0)
					res = Math.max(res, val[--r]);
			}
			return res;
		}
	}

	static boolean check(int i, int j, int n) {
		if (i >= 0 && j >= 0 && i < n && j < n)
			return true;
		return false;
	}

	public static int[] generateDivisorTable(int n) {
		int[] divisor = new int[n + 1];
		for (int i = 1; i <= n; i++)
			divisor[i] = i;
		for (int i = 2; i * i <= n; i++)
			if (divisor[i] == i)
				for (int j = i * i; j <= n; j += i)
					divisor[j] = i;
		return divisor;
	}

	public static int[][] matrixMul(int[][] a, int[][] b) {
		int n = a.length;
		int m = a[0].length;
		int k = b[0].length;
		int[][] res = new int[n][k];
		for (int i = 0; i < n; i++) {
			for (int j = 0; j < k; j++) {
				for (int p = 0; p < m; p++) {
					res[i][j] = (res[i][j] + (int) ((a[i][p] * 1l * b[p][j]) % mod)) % mod;
				}
			}
		}
		return res;
	}

	public static int[][] matrixPow(int[][] a, int p) {
		if (p == 0) {
			return matrixUnit(a.length);
		} else if (p % 2 == 0) {
			return matrixPow(matrixMul(a, a), p / 2);
		} else {
			return matrixMul(a, matrixPow(a, p - 1));
		}
	}

	public static int[][] matrixUnit(int n) {
		int[][] res = new int[n][n];
		for (int i = 0; i < n; ++i) {
			res[i][i] = 1;
		}
		return res;
	}

	static int[] modInv(int n, int mod) {
		int[] ans = new int[n];
		for (int i = 1; i < n; i++)
			ans[i] = (int) pow(i, mod - 2, mod);
		return ans;
	}

	static int[] primes;

	public static long ncr(int n, int r) {
		if (n < r)
			return 0;
		if (n == r)
			return 1;
		if (r == 0)
			return 1;
		if (r < 0)
			return 0;
		long ans = 1;
		for (int i = 0; i < primes.length; i++) {
			long power = count(n, primes[i]) - count(n - r, primes[i]) - count(r, primes[i]);
			ans *= pow(primes[i], power, mod);
			ans %= mod;
		}
		return ans;
	}

	public static long pow(long x, long n, int mod) {
		long res = 1;
		for (long p = x; n > 0; n >>= 1, p = (p * p) % mod) {
			if ((n & 1) != 0) {
				res = (int) (res * p % mod);
			}
		}
		return res;
	}

	public static long count(int n, int p) {
		long count = 0;
		long z = p;
		while (z <= n) {
			count += n / z;
			z *= p;
		}
		return count;

	}

	public static int[] generatePrimes(int n) {
		boolean[] prime = new boolean[n + 1];
		Arrays.fill(prime, 2, n + 1, true);
		for (int i = 2; i * i <= n; i++)
			if (prime[i])
				for (int j = i * i; j <= n; j += i)
					prime[j] = false;
		int[] primes = new int[n + 1];
		int cnt = 0;
		for (int i = 0; i < prime.length; i++)
			if (prime[i])
				primes[cnt++] = i;

		return Arrays.copyOf(primes, cnt);
	}

	static class Pairxy implements Comparable<Pairxy> {
		int x;
		int y;

		Pairxy(int x, int y) {
			this.x = x;
			this.y = y;
		}

		public int compareTo(Pairxy o) {
			return Integer.compare(this.x, o.x);
		}

	}

	static class Pair implements Comparable<Pair> {
		long val;
		int ind;

		Pair(long v, int i) {
			val = v;
			ind = i;
		}

		public int compareTo(Pair o) {
			if (this.val != o.val)
				return Long.compare(this.val, o.val);
			return Integer.compare(this.ind, o.ind);
		}
	}

	public static long C(int n, int r) {
		long ans = 1;
		int x = 1;
		while (x <= r) {
			ans *= n;
			ans /= x;
			x++;
			n--;
		}
		return ans;
	}

	static class DisjointSetsRank {

		int[] p;
		int[] rank;

		public DisjointSetsRank(int size) {
			p = new int[size];
			for (int i = 0; i < size; i++)
				p[i] = i;
			rank = new int[size];
		}

		public int root(int x) {
			return x == p[x] ? x : (p[x] = root(p[x]));
		}

		public int sameSet(int x, int y) {
			if (root(x) == root(y))
				return 1;
			return 0;

		}

		public void unite(int a, int b) {
			a = root(a);
			b = root(b);
			if (a == b)
				return;

			if (rank[a] < rank[b]) {
				p[a] = b;
			} else {
				p[b] = a;
				if (rank[a] == rank[b])
					++rank[a];
			}
		}

	}

	static int gcd(long m, long n) {
		long x;
		long y;
		while (m % n != 0) {
			x = n;
			y = m % n;
			m = x;
			n = y;
		}
		return (int) n;
	}

	static class FasterScanner {
		private byte[] buf = new byte[1024];
		private int curChar;
		private int snumChars;

		public int read() {
			if (snumChars == -1)
				throw new InputMismatchException();
			if (curChar >= snumChars) {
				curChar = 0;
				try {
					snumChars = System.in.read(buf);
				} catch (IOException e) {
					throw new InputMismatchException();
				}
				if (snumChars <= 0)
					return -1;
			}
			return buf[curChar++];
		}

		public String nextLine() {
			int c = read();
			while (isSpaceChar(c))
				c = read();
			StringBuilder res = new StringBuilder();
			do {
				res.appendCodePoint(c);
				c = read();
			} while (!isEndOfLine(c));
			return res.toString();
		}

		public String nextString() {
			int c = read();
			while (isSpaceChar(c))
				c = read();
			StringBuilder res = new StringBuilder();
			do {
				res.appendCodePoint(c);
				c = read();
			} while (!isSpaceChar(c));
			return res.toString();
		}

		public long nextLong() {
			int c = read();
			while (isSpaceChar(c))
				c = read();
			int sgn = 1;
			if (c == '-') {
				sgn = -1;
				c = read();
			}
			long res = 0;
			do {
				if (c < '0' || c > '9')
					throw new InputMismatchException();
				res *= 10;
				res += c - '0';
				c = read();
			} while (!isSpaceChar(c));
			return res * sgn;
		}

		public int nextInt() {
			int c = read();
			while (isSpaceChar(c))
				c = read();
			int sgn = 1;
			if (c == '-') {
				sgn = -1;
				c = read();
			}
			int res = 0;
			do {
				if (c < '0' || c > '9')
					throw new InputMismatchException();
				res *= 10;
				res += c - '0';
				c = read();
			} while (!isSpaceChar(c));
			return res * sgn;
		}

		public int[] nextIntArray(int n) {
			int[] arr = new int[n];
			for (int i = 0; i < n; i++) {
				arr[i] = nextInt();
			}
			return arr;
		}

		public long[] nextLongArray(int n) {
			long[] arr = new long[n];
			for (int i = 0; i < n; i++) {
				arr[i] = nextLong();
			}
			return arr;
		}

		private boolean isSpaceChar(int c) {
			return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
		}

		private boolean isEndOfLine(int c) {
			return c == '\n' || c == '\r' || c == -1;
		}
	}
}