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//Franciszek Witt
#include<bits/stdc++.h>
using namespace std;
#define FOR(i,l,r) for(int i=(l);i<=(r);++i)
#define REP(i,n) FOR(i,0,(n)-1)
#define ssize(x) int(x.size())
template<class A,class B>auto&operator<<(ostream&o,pair<A,B>p){return o<<'('<<p.first<<", "<<p.second<<')';}
template<class T>auto operator<<(ostream&o,T x)->decltype(x.end(),o){o<<'{';int i=0;for(auto e:x)o<<(", ")+2*!i++<<e;return o<<'}';}
#ifdef DEBUG
#define debug(x...) cerr<<"["#x"]: ",[](auto...$){((cerr<<$<<"; "),...);}(x),cerr<<'\n'
#else
#define debug(...) {}
#endif
typedef long long ll;
const int mod = int(1e9) + 7;
int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    int n, q;
    cin >> n >> q;
    
    auto nrm = [&] (int x) {
        x %= 3;
        if(x < 0)
            x += 3;
        return x;
    };
    
    vector re(3, vector(n + 1, 0LL));
    re[0][0] = 1LL;
    FOR(i, 1, n)
        REP(j, 3)
            re[j][i] = (re[j][i - 1] + re[nrm(j - 1)][i - 1]) % mod;

    int miss0 = 0, miss1 = 0, ze = 0, je = 0, idk = 0;
    auto upd = [&] (int x, int y, int sig) {
        if(y == -1) {
            idk += sig;
            return;
        }
        if((x + y) & 1)
            miss0 += sig;
        else
            miss1 += sig;
        if(y == 0)
            ze += sig;
        if(y == 1)
            je += sig;
    };
    vector<int> ve;
    {
        string s;
        cin >> s;
        REP(i, n) {
            if(s[i] == 'C') {
                ve.emplace_back(0);
            }
            else if(s[i] == 'Z') {
                ve.emplace_back(1);
            }
            else {
                ve.emplace_back(-1);
            }
            upd(i, ve.back(), 1);
        }
    }

    auto gw = [&] () {
        ll wy = 0;
        auto prmiss = [&] (int ban) {
            if(n == 1)
                return;
            if((n / 2) % 3 != ban)
                wy -= !miss0;
            if(((n + 1) / 2) % 3 != ban)
                wy -= !miss1;
        };
        if(n % 3 == 0) {
            wy = re[nrm(1 - je)][idk] + re[nrm(2 - je)][idk];
            prmiss(0);
        }
        else if(n % 3 == 1) {
            wy = re[nrm(0 - je)][idk] + re[nrm(1 - je)][idk];
            prmiss(2);
        }
        else if(n % 3 == 2) {
            wy = re[nrm(0 - je)][idk] + re[nrm(2 - je)][idk];
            prmiss(1);
        }
        wy %= mod;
        wy += mod;
        wy %= mod;
        return wy;
    };

    cout << gw() << endl;
    REP(qq, q) {
        int x;
        char cc = 0;
        int val = 0;
        cin >> x;
        --x;
        while(cc != 'C' && cc != 'Z' && cc != 'N')
            cin >> cc;
        if(cc == 'N')
            val = -1;
        else if(cc == 'Z')
            val = 1;
        else if(cc == 'C')
            val = 0;
        upd(x, ve[x], -1);
        upd(x, val, 1);
        ve[x] = val;
        cout << gw() << "\n";
    }
    
}