#include <cstdio>
#include <iostream>
#include <algorithm>
#include <vector>
#include <queue>
#include <map>
using namespace std;

// #define Debug

const int N = 5000, M = 5e5;
const int E = M << 1;

int n, m, q;
int col[N + 5];

int head[N + 5], to[E + 5], nxt[E + 5], tot = 1;
void add_edge(int u, int v)
{
	tot++;
	to[tot] = v;
	nxt[tot] = head[u];
	head[u] = tot;
	return ;
}
void add(int u, int v)
{
	add_edge(u, v);
	add_edge(v, u);
	return ;
}

vector<int> e[N + 5];
int ans[N + 5][N + 5];

int vis[N + 5];
bool dfs1(int u, int fa)
{
	if (fa)
		e[u].push_back(fa), e[fa].push_back(u);

	bool res = true;
	for (int i = head[u]; i; i = nxt[i])
	{
		int v = to[i];
		if (col[u] != col[v])
			continue;

		if (vis[v])
			res &= (vis[v] != vis[u]);
		else
		{
			vis[v] = 3 - vis[u];
			res &= dfs1(v, u);
		}
	}
	return res;
}
void dfs2(int u, int fa)
{
	if (fa)
		e[u].push_back(fa), e[fa].push_back(u);

	for (int i = head[u]; i; i = nxt[i])
	{
		int v = to[i];
		if (col[u] == col[v] || !vis[v])
			continue;

		vis[v] = 0;
		dfs2(v, u);
	}
	return ;
}

typedef pair<int, int> pir;
queue<pir> que;
void build()
{
	for (int u = 1; u <= n; u++)
	{
		ans[u][u] = 1;
		que.emplace(u, u);

		for (auto v : e[u])
		{
			if (col[u] != col[v] || ans[u][v])//if their's a self-circle
				continue;

			ans[u][v] = 1;
			que.emplace(u, v);
		}
	}

	while (!que.empty())
	{
		auto t = que.front();
		que.pop();

		int u = t.first, v = t.second;
		for (auto uu : e[u])
		for (auto vv : e[v])
		{
			if (col[uu] != col[vv] || ans[uu][vv])
				continue;

			ans[uu][vv] = 1;
			que.emplace(uu, vv);
		}
	}
	return ;
}

int main()
{
	// freopen("tour.in", "r", stdin);
	// freopen("tour.out", "w", stdout);

	scanf("%d%d%d", &n, &m, &q);
	for (int i = 1; i <= n; i++)
		scanf("%1d", col + i);
	for (int i = 1, u, v; i <= m; i++)
	{
		scanf("%d%d", &u, &v);
		add(u, v);
	}

	for (int u = 1; u <= n; u++)
	{
		if (vis[u])
			continue;
		
		vis[u] = 1;
		bool res = dfs1(u, 0);
		if (!res)
			e[u].push_back(u);
	}
	for (int u = 1; u <= n; u++)
	{
		if (!vis[u])
			continue;
		
		vis[u] = 0;
		dfs2(u, 0);
	}

	build();
	for (int i = 1, u, v; i <= q; i++)
	{
		scanf("%d%d", &u, &v);
		if (ans[u][v])
			puts("YES");
		else
			puts("NO");
	}
	return 0;
}