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// Karol Kosinski 2022
#include <bits/stdc++.h>
#define FOR(i,a,b) for(int i=(a),_b=(b);i<_b;++i)
#define FR_(i,a,b) for(int i=(a),_b=(b);i<=_b;++i)
#define FD_(i,b,a) for(int i=(b),_a=(a);i>=_a;--i)
#define ALL(c) (c).begin(),(c).end()
#define SIZE(c) int((c).size())
#define TIE(x...) int x;tie(x)
#define X first
#define Y second
#ifndef ENABLE_DEBUG
#define DEB(k,p,f,x...)
#else
#define DEB(k,p,f,x...) {if(k)printf("--------%4d : %s\n",__LINE__,__FUNCTION__);if(p)f(x);}
#endif
#define DEBL DEB(1,1,void,0)
#define DEBF(f,x...) DEB(1,1,f,x)
#define DEBC(p,x...) DEB(0,p,printf,x)
#define DEBUG(x...) DEB(0,1,printf,x)
using namespace std;
using LL = long long;
using ULL = unsigned long long;
using PII = pair<int, int>;
using TIII = tuple<int, int, int>;

constexpr int NX = 200'005;
constexpr LL MOD = 1e9 + 7;

struct Monoid
{
    enum Elem { A, B, o, a, b, c, z };
    static const Elem M[7][7];

    LL S[7];

    void set(char ch)
    {
        FOR(i,0,7) S[i] = 0;
        switch (ch)
        {
            case 'C': S[a] = 1; break;
            case 'Z': S[b] = 1; break;
            case 'N': S[a] = S[b] = 1; break;
        }
    }

    bool is_zeroed() const
    {
        FOR(i,0,7) if ( S[i] != 0 ) return false;
        return true;
    }
};

const Monoid::Elem Monoid::M[7][7] = {
    { B, o, A, B, o, A, A },
    { o, A, B, o, A, B, B },
    { A, B, o, A, B, o, o },
    { B, o, A, B, c, A, a },
    { o, A, B, z, A, b, B },
    { A, B, o, a, B, c, o },
    { A, B, o, A, b, o, z }
};

void deb_write(const Monoid& x)
{
    DEBUG("{ ");
    FOR(i,0,7) DEBUG("%3lld", x.S[i]);
    DEBUG(" }\n");
}

void add(const Monoid& x, const Monoid& y, Monoid& output)
{
    if ( x.is_zeroed() )
    {
        output = y;
        return;
    }
    if ( y.is_zeroed() )
    {
        output = x;
        return;
    }
    FOR(i,0,7) output.S[i] = 0;
    FOR(i,0,7)
    {
        const auto& xi = x.S[i];
        if ( xi == 0 ) continue;
        FOR(j,0,7)
        {
            auto& ot = output.S[ Monoid::M[i][j] ];
            ot = ( ot + ( xi * y.S[j] ) % MOD ) % MOD;
        }
    }
}

template <int N>
struct SumTree
{
    static constexpr int R2K(int x) { int r = 1; while ( r < x ) r <<= 1; return r; }

    int n;
    Monoid Sum[ R2K(N) << 1 ];

    void init(int nt, char* t = nullptr)
    {
        int n0 = t ? nt : 0;
        n = R2K(nt);
        FOR(i,0,n0) Sum[ n + i ].set( t[i] );
        FOR(i,n0,n) Sum[ n + i ].set(0);
        FD_( i, n - 1 , 1 )
        {
            add( Sum[ i << 1 ], Sum[ i << 1 | 1 ], Sum[i] );
            DEBF(deb_write, Sum[i]);
        }
    }

    void set(int x, char v)
    {
        DEBF(write_row);
        for ( Sum[ x += n ].set(v); x > 1; x >>= 1 )
        {
            DEBF(deb_write, Sum[x]);
            DEBF(deb_write, Sum[ x ^ 1 ]);
            DEBUG("** %d\n", x);
            if ( x & 1 == 1 )
                add( Sum[ x ^ 1 ],  Sum[x], Sum[ x >> 1 ] );
            else
                add( Sum[x],  Sum[ x ^ 1 ], Sum[ x >> 1 ] );
        }
        DEBF(deb_write, Sum[x]);
        DEBUG("** %d\n", x);
    }

    Monoid top() const
    {
        return Sum[1];
    }

    void write_row()
    {
        FOR(i,0,n) deb_write(Sum[ n + i ]);
    }
};

char Str[NX];
SumTree<NX> T {};

void write(int n)
{
    auto res = T.top();
    DEBF(deb_write, res);
    if ( n == 1 )
        printf("%lld\n", ( res.S[Monoid::a] + res.S[Monoid::b] ) % MOD );
    else
        printf("%lld\n", ( res.S[Monoid::A] + res.S[Monoid::B] ) % MOD );
    DEBUG("\n\n");
}

int main()
{
    int n, q;
    scanf("%d%d%s", &n, &q, Str);
    T.init(n, Str);
    write(n);
    FOR(i,0,q)
    {
        int k; char ch[2];
        scanf("%d%s", &k, ch);
        T.set( k - 1, ch[0] );
        write(n);
    }
    return 0;
}