#include <bits/stdc++.h>

using namespace std;

const int N = 5e3;

int n, m, k;
int a[N + 5], col[N + 5];
vector<int> g[N + 5], e[N + 5];
bool f[N + 5][N + 5];

bool dfs0(int c, int u) {
  bool ret = 1;
  for (int v : g[u]) {
    if (a[v] != c) continue;
    if (!~col[v]) col[v] = col[u] ^ 1, e[u].push_back(v), e[v].push_back(u), ret &= dfs0(c, v);
    else if (col[u] == col[v]) ret = 0;
  }
  return ret;
}
bool vis[N + 5];
void dfs1(int u) {
  vis[u] = 1;
  for (int v : g[u]) {
    if (a[u] == a[v] || vis[v]) continue;
    e[u].push_back(v), e[v].push_back(u), dfs1(v);
  }
}

int main() {
  scanf("%d%d%d", &n, &m, &k);
  for (int i = 1; i <= n; ++i) scanf("%1d", a + i);
  for (int i = 1; i <= m; ++i) {
    int u, v; scanf("%d%d", &u, &v), g[u].push_back(v), g[v].push_back(u);
  }
  fill_n(col + 1, n, -1);
  for (int i = 1; i <= n; ++i) {
    if (!~col[i]) {
      col[i] = 0;
      if (!dfs0(a[i], i)) e[i].push_back(i);
    }
    if (!vis[i]) dfs1(i);
  }
  queue<pair<int, int>> q;
  for (int i = 1; i <= n; ++i) f[i][i] = 1, q.emplace(i, i);
  for (int i = 1; i <= n; ++i)
    for (int j : e[i])
      if (a[j] == a[i])
        f[i][j] = 1, q.emplace(i, j);
  while (!q.empty()) {
    auto [u, v] = q.front(); q.pop();
    for (int i : e[u])
      for (int j : e[v])
        if (a[i] == a[j] && !f[i][j]) f[i][j] = 1, q.emplace(i, j);
  }
  for (; k; --k) {
    int u, v; scanf("%d%d", &u, &v), puts(f[u][v] ? "YES" : "NO");
  }
}