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// Arti1990, II UWr

#include <bits/stdc++.h>

#define forr(i, n)                  for(int i=0; i<n; i++)
#define FOREACH(iter, coll)         for(auto iter = coll.begin(); iter != coll.end(); ++iter)
#define FOREACHR(iter, coll)        for(auto iter = coll.rbegin(); iter != coll.rend(); ++iter)
#define lbound(P,K,FUN)             ({auto SSS=P, PPP = P-1, KKK=(K)+1; while(PPP+1!=KKK) {SSS = (PPP+(KKK-PPP)/2); if(FUN(SSS)) KKK = SSS; else PPP = SSS;} PPP;})
#define testy()                     int _tests; scanf("%d", &_tests); FOR(_test, 1, _tests)
#define CLEAR(tab)                  memset(tab, 0, sizeof(tab))
#define CONTAIN(el, coll)           (coll.find(el) != coll.end())
#define FOR(i, a, b)                for(int i=a; i<=b; i++)
#define FORD(i, a, b)               for(int i=a; i>=b; i--)
#define MP                          make_pair
#define PB                          push_back
#define ff                          first
#define ss                          second
#define deb(X)                      X;

#define M 1000000007
#define INF 1000000007LL

using namespace std;

int n, m, tab[200007], a;
long long dp[200007][3];
int ile[3][2], numer[128], suma;
string slowo;
char c;

void init()
{
    numer['Z'] = 1;
    numer['C'] = 2;
    dp[0][0] = 1;
    FOR(i, 1, 200003)
        forr(j, 3)
        {
            dp[i][j] = (dp[i-1][(j+1)%3] + dp[i-1][(j+2)%3]) % M;
            //cout << dp[i][j] << " ";
        }
}

long long policz()
{
/*    forr(i, 3)
    {
        cout << "ile " << i << ":";
        forr(j, 2)
            cout << " " << ile[i][j];
        cout << '\n';
    }
*/
    long long res = 0;
    forr(i, 3)
        if((i+suma)%3 != 0)
            res += dp[ile[0][0] + ile[0][1]][i];

    if(n > 1 && ile[1][0] == 0 && ile[2][1] == 0 && n%2 == 1)
        res--;
    if(n > 1 && ile[1][1] == 0 && ile[2][0] == 0 && n%2 == 1)
        res--;

    return (res + M)%M;
}

int solve()
{
    cin >> n >> m;
    cin >> slowo;
    FOR(i, 1, n)
    {
        tab[i] = numer[slowo[i-1]];
        ile[tab[i]][i%2]++;
        suma += tab[i];
    }
    cout << policz() << '\n';

    forr(i, m)
    {
        cin >> a >> c;
        ile[tab[a]][a%2]--;
        suma -= tab[a];
        tab[a] = numer[c];
        ile[tab[a]][a%2]++;
        suma += tab[a];

        cout << policz() << '\n';
    }

    return 0;
}

int main()
{
    std::ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    init();

    solve();

    return 0;
}