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#include <bits/stdc++.h>
using namespace std;
const int MX=270100,md=1000000007;
int q,n,nn,i,pos,pw2[MX],b[MX*2][3],cc[2],zz[2];
char s[MX],c[5];
void upd(int& x, int v) {
  if ((x+=v)>=md) x-=md;
}
void init(int i, int L, int R) {
  if (L==R) {
    b[i][0]=int(s[R-1]!='Z');
    b[i][1]=int(s[R-1]!='C');
    b[i][2]=0;
    if (s[R-1]=='N') ++nn;
    if (s[R-1]=='C') ++cc[R%2];
    if (s[R-1]=='Z') ++zz[R%2];
    return;
  }
  int mid=(L+R)/2;
  init(i*2,L,mid);
  init(i*2+1,mid+1,R);
  for (int j=0; j<3; j++) b[i][j]=0;
  for (int j=0; j<3; j++) for (int k=0; k<3; k++) upd(b[i][(j+k)%3],(1LL*b[i*2][j]*b[i*2+1][k])%md);
}
void mdf(int i, int L, int R, int pos, char c) {
  if (L==R) {
    b[i][0]=int(c!='Z');
    b[i][1]=int(c!='C');
    b[i][2]=0;
    if (s[R-1]=='N') --nn;
    if (s[R-1]=='C') --cc[R%2];
    if (s[R-1]=='Z') --zz[R%2];
    s[R-1]=c;
    if (s[R-1]=='N') ++nn;
    if (s[R-1]=='C') ++cc[R%2];
    if (s[R-1]=='Z') ++zz[R%2];
    return;
  }
  int mid=(L+R)/2;
  if (pos<=mid) mdf(i*2,L,mid,pos,c); else mdf(i*2+1,mid+1,R,pos,c);
  for (int j=0; j<3; j++) b[i][j]=0;
  for (int j=0; j<3; j++) for (int k=0; k<3; k++) upd(b[i][(j+k)%3],(1LL*b[i*2][j]*b[i*2+1][k])%md);
}
void solve() {
  int bad=0;
  if (n>1) {
    bad=b[1][(3-n%3)%3];
    if (n%2==1) {
      if (cc[0]==0 && zz[1]==0) upd(bad,1);
      if (cc[1]==0 && zz[0]==0) upd(bad,1);
    }
  }
  printf("%d\n",(pw2[nn]+md-bad)%md);
}
int main() {
  scanf("%d%d",&n,&q);
  for (pw2[0]=i=1; i<=n; i++) pw2[i]=(pw2[i-1]*2)%md;
  scanf("%s",s);
  init(1,1,n);
  solve();
  while (q--) {
    scanf("%d",&pos);
    scanf("%s",c);
    mdf(1,1,n,pos,c[0]);
    s[pos-1]=c[0];
    solve();
  }
  return 0;
}