/* -*- coding: utf-8 -*-
 *
 * 3291.cc:  No.3291 K-step Navigation - yukicoder
 */

#include<cstdio>
#include<vector>
#include<queue>
#include<algorithm>

using namespace std;

/* constant */

const int MAX_N = 2000;
const int MAX_N2 = MAX_N * 2;

/* typedef */

using ll = long long;
using vi = vector<int>;
using qi = queue<int>;

/* global variables */

bool es[MAX_N][MAX_N];
vi nbrs[MAX_N];
int sds[MAX_N2], tds[MAX_N2];

/* subroutines */

void bfs(int n, int st, int ds[]) {
  fill(ds, ds + n * 2, -1);
  ds[st << 1] = 0;
  qi q;
  q.push(st << 1);

  while (! q.empty()) {
    int u = q.front(); q.pop();
    int ux = (u >> 1), up = (u & 1);
    int vd = ds[u] + 1;
    for (auto vx: nbrs[ux]) {
      int v = (vx << 1) | (up ^ 1);
      if (ds[v] < 0) ds[v] = vd, q.push(v);
    }
  }
}

/* main */

int main() {
  int n, m, s, t;
  ll k;
  scanf("%d%d%lld%d%d", &n, &m, &k, &s, &t);
  s--, t--;
  for (int i = 0; i < m; i++) {
    int u, v;
    scanf("%d%d", &u, &v);
    u--, v--;
    es[u][v] = es[v][u] = true;
    nbrs[u].push_back(v);
    nbrs[v].push_back(u);
  }

  bfs(n, s, sds);
  bfs(n, t, tds);

  int d0 = sds[(t << 1) | (k & 1)];
  if (d0 >= 0 && d0 <= k) {
    puts("Yes");
    return 0;
  }

  for (int ux = 0; ux < n; ux++)
    for (int vx = 0; vx < n; vx++)
      if (ux != vx && ! es[ux][vx])
	for (int up = 0; up < 2; up++)
	  for (int vp = 0; vp < 2; vp++) {
	    int u = (ux << 1) | up;
	    int v = (vx << 1) | vp;
	    if (sds[u] >= 0 && tds[v] >= 0 &&
		sds[u] + 1 + tds[v] <= k &&
		(up ^ vp ^ 1) == (k & 1)) {
	      puts("Yes");
	      //printf(" ux=%d,vx=%d\n", ux + 1, vx + 1);
	      return 0;
	    }
	  }

  puts("No");
  return 0;
}