#include<vector>
#include<cstdio>
#include<queue>
#include<algorithm>
#define MN 410001
using namespace std;

int n,m,x[MN],bo[MN][2],y[MN],ln;
char s[MN];
vector <int> v[MN];
bool B[MN];
queue<int> q;
int main(){
	scanf("%d%d",&n,&m);
	scanf("%s",s+1);
	for (int i=1;i<=n;i++) s[i]=s[i]=='B',B[i]=1;
	for (int i=1;i<=m;i++){
		scanf("%d%d",&x[i],&y[i]);
		v[x[i]].push_back(y[i]);
		v[y[i]].push_back(x[i]);
		bo[x[i]][s[y[i]]]++;bo[y[i]][s[x[i]]]++;
	}
	for (int i=1;i<=n;i++)
	if (!bo[i][0]||!bo[i][1]) q.push(i),B[i]=0;
	while (!q.empty()){
		ln++;
		int k=q.front();q.pop();
		for (int i=0;i<v[k].size();i++)
		if (--bo[v[k][i]][s[k]]==0&&B[v[k][i]]) q.push(v[k][i]),B[v[k][i]]=0;
	}
	puts(ln==n?"No":"Yes");
} 
### Prompt

Please formulate a Cpp solution to the following problem:

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<vector>
#include<cstdio>
#include<queue>
#include<algorithm>
#define MN 410001
using namespace std;

int n,m,x[MN],bo[MN][2],y[MN],ln;
char s[MN];
vector <int> v[MN];
bool B[MN];
queue<int> q;
int main(){
	scanf("%d%d",&n,&m);
	scanf("%s",s+1);
	for (int i=1;i<=n;i++) s[i]=s[i]=='B',B[i]=1;
	for (int i=1;i<=m;i++){
		scanf("%d%d",&x[i],&y[i]);
		v[x[i]].push_back(y[i]);
		v[y[i]].push_back(x[i]);
		bo[x[i]][s[y[i]]]++;bo[y[i]][s[x[i]]]++;
	}
	for (int i=1;i<=n;i++)
	if (!bo[i][0]||!bo[i][1]) q.push(i),B[i]=0;
	while (!q.empty()){
		ln++;
		int k=q.front();q.pop();
		for (int i=0;i<v[k].size();i++)
		if (--bo[v[k][i]][s[k]]==0&&B[v[k][i]]) q.push(v[k][i]),B[v[k][i]]=0;
	}
	puts(ln==n?"No":"Yes");
} 
```