#include<cstdio>
#include<vector>
#include<queue>
using namespace std;
const int MAXN=200005;

int N,M;
char s[MAXN];
vector<int> adj[MAXN];
int cnt[MAXN][2];
queue<int> Q;
bool del[MAXN];

int main()
{
    scanf("%d%d%s",&N,&M,s+1);
    for(int i=1;i<=M;i++)
    {
        int a,b;
        scanf("%d%d",&a,&b);
        adj[a].push_back(b);
        adj[b].push_back(a);
        cnt[a][s[b]-'A']++;
        cnt[b][s[a]-'A']++;
    }
    for(int i=1;i<=N;i++)
        if(cnt[i][0]==0||cnt[i][1]==0)
            Q.push(i),del[i]=true;
    int tmp=0;
    while(!Q.empty())
    {
        int u=Q.front();
        Q.pop();
        tmp++;
        for(auto v:adj[u])
            if(!del[v])
            {
                cnt[v][s[u]-'A']--;
                if(cnt[v][s[u]-'A']==0)
                {
                    del[v]=true;
                    Q.push(v);
                }
            }
    }
    if(tmp<N)
        puts("Yes");
    else
        puts("No");

    return 0;
}

### Prompt

Develop a solution in CPP to the problem described below:

You are given an undirected graph consisting of N vertices and M edges. The vertices are numbered 1 to N, and the edges are numbered 1 to M. In addition, each vertex has a label, `A` or `B`. The label of Vertex i is s_i. Edge i bidirectionally connects vertex a_i and b_i.

The phantom thief Nusook likes to choose some vertex as the startpoint and traverse an edge zero or more times. Today, he will make a string after traveling as above, by placing the labels of the visited vertices in the order visited, beginning from the startpoint.

For example, in a graph where Vertex 1 has the label `A` and Vertex 2 has the label `B`, if Nusook travels along the path 1 \rightarrow 2 \rightarrow 1 \rightarrow 2 \rightarrow 2, the resulting string is `ABABB`.

Determine if Nusook can make all strings consisting of `A` and `B`.

Constraints

* 2 \leq N \leq 2 \times 10^{5}
* 1 \leq M \leq 2 \times 10^{5}
* |s| = N
* s_i is `A` or `B`.
* 1 \leq a_i, b_i \leq N
* The given graph may NOT be simple or connected.

Input

Input is given from Standard Input in the following format:


N M
s
a_1 b_1
:
a_{M} b_{M}


Output

If Nusook can make all strings consisting of `A` and `B`, print `Yes`; otherwise, print `No`.

Examples

Input

2 3
AB
1 1
1 2
2 2


Output

Yes


Input

4 3
ABAB
1 2
2 3
3 1


Output

No


Input

13 23
ABAAAABBBBAAB
7 1
10 6
1 11
2 10
2 8
2 11
11 12
8 3
7 12
11 2
13 13
11 9
4 1
9 7
9 6
8 13
8 6
4 10
8 7
4 3
2 1
8 12
6 9


Output

Yes


Input

13 17
BBABBBAABABBA
7 1
7 9
11 12
3 9
11 9
2 1
11 5
12 11
10 8
1 11
1 8
7 7
9 10
8 8
8 12
6 2
13 11


Output

No

### Response

```cpp
#include<cstdio>
#include<vector>
#include<queue>
using namespace std;
const int MAXN=200005;

int N,M;
char s[MAXN];
vector<int> adj[MAXN];
int cnt[MAXN][2];
queue<int> Q;
bool del[MAXN];

int main()
{
    scanf("%d%d%s",&N,&M,s+1);
    for(int i=1;i<=M;i++)
    {
        int a,b;
        scanf("%d%d",&a,&b);
        adj[a].push_back(b);
        adj[b].push_back(a);
        cnt[a][s[b]-'A']++;
        cnt[b][s[a]-'A']++;
    }
    for(int i=1;i<=N;i++)
        if(cnt[i][0]==0||cnt[i][1]==0)
            Q.push(i),del[i]=true;
    int tmp=0;
    while(!Q.empty())
    {
        int u=Q.front();
        Q.pop();
        tmp++;
        for(auto v:adj[u])
            if(!del[v])
            {
                cnt[v][s[u]-'A']--;
                if(cnt[v][s[u]-'A']==0)
                {
                    del[v]=true;
                    Q.push(v);
                }
            }
    }
    if(tmp<N)
        puts("Yes");
    else
        puts("No");

    return 0;
}

```