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//~ while (clock()<=69*CLOCKS_PER_SEC)
//~ #pragma comment(linker, "/stack:200000000")
#pragma GCC optimize("O3")
//~ #pragma GCC optimize("Ofast")
//~ #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
//~ #pragma GCC optimize("unroll-loops")

#include <bits/stdc++.h>

using namespace std;

using ll=long long;
using ld=long double;
using pii=pair<int, int>;
using pll=pair<ll, ll>;
using vi=vector<int>;
using vll=vector<ll>;

template<class TH> void _dbg(const char *sdbg, TH h){ cerr<<sdbg<<" = "<<h<<endl; }
#ifdef LOCAL
#define _upgrade ios_base::sync_with_stdio(0);
#define debug(...) _dbg(#__VA_ARGS__, __VA_ARGS__);
#else
#define _upgrade ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
#define debug(...) 98;
#define cerr if(0) cout
#endif

#define pb push_back
#define mp make_pair
#define all(x) x.begin(),x.end()
#define sz(x) ((int)(x).size())
#define fi first
#define se second

#define erase_duplicates(x) sort(all(x)), (x).resize(distance((x).begin(), unique(all(x))));

#define watch(x) cout << (#x) << " is " << (x) << endl;

#define pow2(x) ((x)*(x))
#define mod(x, m) ((((x) % (m)) + (m)) % (m))
#define max3(a, b, c) max(a, max(b, c))
#define min3(a, b, c) min(a, min(b, c))

#define REP(i, a, b) for(int i = a; i <= b; ++i)
#define REPV(i, b, a) for(int i = b; i >= a; --i)

const double m_pi = acos(-1.0);
const int int_max = 0x3f3f3f3f;
const int M7 = 1000*1000*1000+7;
const int M9 = 1000*1000*1000+9;

int mod = M7;
int pow2[200'001];
int tab[200'001][3];

int calcbadchainred(char c, int i) {
    if(i%2==0) {
        if(c == 'Z') return 1;
    } else {
        if(c == 'C') return 1;
    }
    return 0;
}
int calcbadchaingreen(char c, int i) {
    if(i%2==0) {
        if(c == 'C') return 1;
    } else {
        if(c == 'Z') return 1;
    }
    return 0;
}

void calcpow2() {
    pow2[0] = 1;
    REP(i, 1, 200'000){
        pow2[i]=pow2[i-1]*2;
        if(pow2[i]>mod)pow2[i]-=mod;
    }
}

void calctab(int n) {
    tab[0][0] = 1;
    tab[0][1] = 0;
    tab[0][2] = 0;

    REP(i, 1, n) {
        tab[i][0] = tab[i-1][1] + tab[i-1][2];
        if(tab[i][0]>mod)tab[i][0]-=mod;
        tab[i][1] = tab[i-1][0] + tab[i-1][2];
        if(tab[i][1]>mod)tab[i][1]-=mod;
        tab[i][2] = tab[i-1][0] + tab[i-1][1];
        if(tab[i][2]>mod)tab[i][2]-=mod;
    }
}

int main(){
    _upgrade
    mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
    cout<<fixed<<setprecision(15);
    
    int n,q;cin>>n>>q;
    string s;cin>>s;

    calcpow2();
    calctab(n);

    int numb = 0;
    int numrv = 0;
    int badchainreddiff = 0;
    int badchaingreendiff = 0;
    REP(i,0,n-1) {
        if(s[i] == 'N')++numb;
        if(s[i] == 'C')++numrv;
        if(s[i] == 'Z')numrv+=2;

        badchainreddiff += calcbadchainred(s[i], i);
        badchaingreendiff += calcbadchaingreen(s[i], i);
    }

    // auto calcresult = [&] () {
    //     int allpos = pow2[numb];
    //     int badrvpos = tab[numb][numrv%3];

    //     int result = allpos - badrvpos;
    //     if (result<0)result+=mod;
    //     if(n%2==1 && n > 1) {
    //         if(badchaingreendiff == 0)--result;
    //         if(badchainreddiff == 0)--result;
    //         if(result < 0)result+=mod;
    //     }
    //     return result;
    // };

    int allpos = pow2[numb];
    int badrvpos = tab[numb][numrv%3];

    int result = allpos - badrvpos;
    if (result<0)result+=mod;
    if(n%2==1 && n > 1) {
        if(badchaingreendiff == 0)--result;
        if(badchainreddiff == 0)--result;
        if(result < 0)result+=mod;
    }
    cout << result << '\n';

    REP(i,0,q-1) {
        int k;char c;
        cin>>k>>c;
        --k;

        badchaingreendiff += calcbadchaingreen(c, k);
        badchaingreendiff -= calcbadchaingreen(s[k], k);
        badchainreddiff += calcbadchainred(c, k);
        badchainreddiff -= calcbadchainred(s[k], k);

        if(c == 'N')++numb;
        if(c == 'C')++numrv;
        if(c == 'Z')numrv+=2;

        if(s[k] == 'N')--numb;
        if(s[k] == 'C')--numrv;
        if(s[k] == 'Z')numrv-=2;

        s[k] = c;


        allpos = pow2[numb];
        badrvpos = tab[numb][numrv%3];

        result = allpos - badrvpos;
        if (result<0)result+=mod;
        if(n%2==1 && n > 1) {
            if(badchaingreendiff == 0)--result;
            if(badchainreddiff == 0)--result;
            if(result < 0)result+=mod;
        }

        cout << result << '\n';

    }

    return 0;
}




/*
    __builtin_popcount count total set bits on a given integer
    (use __builtin_popcountll for long long).


*/