#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
int n;
vector<int> v[200000];
string s;
bool b[200000];
void f(int x){
    bool p=false, q=false;
    for(int i=0;i<v[x].size();i++){
        int t=v[x][i];
        if(b[t]){
            if(s[t]=='A')p=true;
            if(s[t]=='B')q=true;
        }
        if(p&&q)return;
    }
    b[x]=false;
    for(int i=0;i<v[x].size();i++){
        if(i>0){
            if(v[x][i]==v[x][i-1])continue;
        }
        int t=v[x][i];
        if(b[t]){
            f(t);
        }
    }
}
int main(void){
    int m;
    cin>>n>>m>>s;
    for(int i=0;i<m;i++){
        int a, b;
        cin>>a>>b;
        a--;
        b--;
        v[a].push_back(b);
        v[b].push_back(a);
    }
    fill(b, b+n, true);
    for(int i=0;i<n;i++){
        sort(v[i].begin(), v[i].end());
    }
    for(int i=0;i<n;i++){
        f(i);
    }
    for(int i=0;i<n;i++){
        if(b[i]){
            cout<<"Yes"<<endl;
            return 0;
        }
    }
    cout<<"No"<<endl;
}

### Prompt

In CPP, your task is to solve 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 <iostream>
#include <algorithm>
#include <vector>
using namespace std;
int n;
vector<int> v[200000];
string s;
bool b[200000];
void f(int x){
    bool p=false, q=false;
    for(int i=0;i<v[x].size();i++){
        int t=v[x][i];
        if(b[t]){
            if(s[t]=='A')p=true;
            if(s[t]=='B')q=true;
        }
        if(p&&q)return;
    }
    b[x]=false;
    for(int i=0;i<v[x].size();i++){
        if(i>0){
            if(v[x][i]==v[x][i-1])continue;
        }
        int t=v[x][i];
        if(b[t]){
            f(t);
        }
    }
}
int main(void){
    int m;
    cin>>n>>m>>s;
    for(int i=0;i<m;i++){
        int a, b;
        cin>>a>>b;
        a--;
        b--;
        v[a].push_back(b);
        v[b].push_back(a);
    }
    fill(b, b+n, true);
    for(int i=0;i<n;i++){
        sort(v[i].begin(), v[i].end());
    }
    for(int i=0;i<n;i++){
        f(i);
    }
    for(int i=0;i<n;i++){
        if(b[i]){
            cout<<"Yes"<<endl;
            return 0;
        }
    }
    cout<<"No"<<endl;
}

```