#include <cstdio>
#include <vector>
const int N = 200064;

int c[N][2], q[N];
char s[N];
bool v[N];
std::vector<int> e[N];

int main() {
	int n, m, a, b;
	scanf("%d%d%s",&n,&m,s+1);
	while (m--) {
		scanf("%d%d",&a,&b);
		e[a].push_back(b);
		e[b].push_back(a);
		c[a][s[b] == 'A']++;
		c[b][s[a] == 'A']++;
	}
	int *h = q, *t = q;
	for (int i = 1; i <= n; i++)
		if (!(c[i][0] && c[i][1]))
			v[*t++ = i] = true;
	for (; h < t; h++)
		for (int x : e[*h])
			if (!v[x] && !--c[x][s[*h] == 'A'])
				v[*t++ = x] = true;
	puts(t == q+n ? "No" : "Yes");
	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>
const int N = 200064;

int c[N][2], q[N];
char s[N];
bool v[N];
std::vector<int> e[N];

int main() {
	int n, m, a, b;
	scanf("%d%d%s",&n,&m,s+1);
	while (m--) {
		scanf("%d%d",&a,&b);
		e[a].push_back(b);
		e[b].push_back(a);
		c[a][s[b] == 'A']++;
		c[b][s[a] == 'A']++;
	}
	int *h = q, *t = q;
	for (int i = 1; i <= n; i++)
		if (!(c[i][0] && c[i][1]))
			v[*t++ = i] = true;
	for (; h < t; h++)
		for (int x : e[*h])
			if (!v[x] && !--c[x][s[*h] == 'A'])
				v[*t++ = x] = true;
	puts(t == q+n ? "No" : "Yes");
	return 0;
}

```