#include <cstdio>
#include <vector>
#include <iostream>
#include <queue>
using namespace std;
const int M = 5005;
#define pb push_back
int read()
{
	int x=0,f=1;char c;
	while((c=getchar())<'0' || c>'9') {if(c=='-') f=-1;}
	while(c>='0' && c<='9') {x=(x<<3)+(x<<1)+(c^48);c=getchar();}
	return x*f;
}
int n,m,k,a[M],b[M],c[M],fa[M][2];bool f[M][M];
vector<int> g[M],G[M];
struct node{int x,y;};queue<node> q;
int find(int x,int t)
{
	if(fa[x][t]==x) return x;
	return fa[x][t]=find(fa[x][t],t);
}
void dfs(int u,int w)
{
	c[u]=w;
	for(int v:G[u])
	{
		if(!c[v]) dfs(v,-w);
		else if(c[v]==w) b[w>0?w:-w]=1;
	}
}
signed main()
{
	n=read();m=read();k=read();
	for(int i=1;i<=n;i++)
	{
		scanf("%1d",&a[i]);
		f[i][i]=1;q.push({i,i});
		fa[i][0]=fa[i][1]=i;
	}
	for(int i=1;i<=m;i++)
	{
		int u=read(),v=read();
		if(a[u]!=a[v])
		{
			int x=find(u,0),y=find(v,0);
			if(x==y) continue;fa[x][0]=y;
			g[u].pb(v);g[v].pb(u);
		}
		else
		{
			int x=find(u,1),y=find(v,1);
			G[u].pb(v);G[v].pb(u);
			if(x==y) continue;fa[x][1]=y;
			g[u].pb(v);g[v].pb(u);
			f[u][v]=f[v][u]=1;q.push({u,v});
		}
	}
	for(int i=1;i<=n;i++)
		if(!c[i]) dfs(i,i);
	for(int i=1;i<=n;i++)
		if(b[i]) g[i].pb(i);
	while(!q.empty())
	{
		int u=q.front().x,v=q.front().y;q.pop();
		for(int x:g[u]) for(int y:g[v])
			if(a[x]==a[y] && !f[x][y])
				q.push({x,y}),f[x][y]=f[y][x]=1;
	}
	while(k--)
	{
		int u=read(),v=read();
		puts(f[u][v]?"YES":"NO");
	}
}