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#include <bits/stdc++.h>

constexpr long long MOD = 1'000'000'007;

long long N, Q, BLUE, RED, GREEN, N_BLUE, N_RED, N_GREEN, P_BLUE, P_RED, P_GREEN;
std::string S;
long long INV_3 = 333'333'336;
long long POW_2[200'005];

void make_pow_2(){
    POW_2[0] = 1;
    for (int i = 1; i < 200'005; ++i)
        POW_2[i] = (POW_2[i - 1] * 2) % MOD;
}

long long F(){
    long long output = POW_2[BLUE];
    if ((N + RED) % 3 == 0){
        if (BLUE % 6 == 0)
            output -= ((POW_2[BLUE] + 2) * INV_3) % MOD;
        else if (BLUE % 6 == 1)
            output -= ((POW_2[BLUE] + 1) * INV_3) % MOD;
        else if (BLUE % 6 == 2)
            output -= ((POW_2[BLUE] - 1) * INV_3) % MOD;
        else if (BLUE % 6 == 3)
            output -= ((POW_2[BLUE] - 2) * INV_3) % MOD;
        else if (BLUE % 6 == 4)
            output -= ((POW_2[BLUE] - 1) * INV_3) % MOD;
        else if (BLUE % 6 == 5)
            output -= ((POW_2[BLUE] + 1) * INV_3) % MOD;
    }
    else if ((N + RED) % 3 == 1){
        if (BLUE % 6 == 0)
            output -= ((POW_2[BLUE] - 1) * INV_3) % MOD;
        else if (BLUE % 6 == 1)
            output -= ((POW_2[BLUE] - 2) * INV_3) % MOD;
        else if (BLUE % 6 == 2)
            output -= ((POW_2[BLUE] - 1) * INV_3) % MOD;
        else if (BLUE % 6 == 3)
            output -= ((POW_2[BLUE] + 1) * INV_3) % MOD;
        else if (BLUE % 6 == 4)
            output -= ((POW_2[BLUE] + 2) * INV_3) % MOD;
        else if (BLUE % 6 == 5)
            output -= ((POW_2[BLUE] + 1) * INV_3) % MOD;
    }
    else{
        if (BLUE % 6 == 0)
            output -= ((POW_2[BLUE] - 1) * INV_3) % MOD;
        else if (BLUE % 6 == 1)
            output -= ((POW_2[BLUE] + 1) * INV_3) % MOD;
        else if (BLUE % 6 == 2)
            output -= ((POW_2[BLUE] + 2) * INV_3) % MOD;
        else if (BLUE % 6 == 3)
            output -= ((POW_2[BLUE] + 1) * INV_3) % MOD;
        else if (BLUE % 6 == 4)
            output -= ((POW_2[BLUE] - 1) * INV_3) % MOD;
        else if (BLUE % 6 == 5)
            output -= ((POW_2[BLUE] - 2) * INV_3) % MOD; 
    }
    if (N % 2 == 1){
        if ((N_GREEN == 0 && N_BLUE > 0 && N_RED == RED) || (P_GREEN == 0 && P_BLUE > 0 && P_RED == RED))
            output += MOD - 1;
    }
    return (output + 3LL * MOD) % MOD;
}

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

    make_pow_2();
    std::cin >> N >> Q >> S;
    
    for (int i = 0; i < N; ++i){
        if (S[i] == 'N')
            ++BLUE;
        else if (S[i] == 'C')
            ++RED;
        else if (S[i] == 'Z')
            ++GREEN;

        if (i % 2)
        {
            if (S[i] == 'N')
                ++N_BLUE;
            else if (S[i] == 'C')
                ++N_RED;
            else if (S[i] == 'Z')
                ++N_GREEN;
        }
        else
        {
            if (S[i] == 'N')
                ++P_BLUE;
            else if (S[i] == 'C')
                ++P_RED;
            else if (S[i] == 'Z')
                ++P_GREEN;
        }
    }
    std::cout << F() << '\n';

    for (int i = 0; i < Q; ++i){
        int M;
        char C;
        std::cin >> M >> C;

        if (C == 'N')
            ++BLUE;
        else if (C == 'C')
            ++RED;
        else if (C == 'Z')
            ++GREEN;

        if ((M - 1) % 2){
            if (C == 'N')
                ++N_BLUE;
            else if (C == 'C')
                ++N_RED;
            else if (C == 'Z')
                ++N_GREEN;
        }
        else{
            if (C == 'N')
                ++P_BLUE;
            else if (C == 'C')
                ++P_RED;
            else if (C == 'Z')
                ++P_GREEN;
        }

        if (S[M - 1] == 'N')
            --BLUE;   
        else if (S[M - 1] == 'C')
            --RED;
        else if (S[M - 1] == 'Z')
            --GREEN;
        
        if ((M - 1) % 2){
            if (S[M - 1] == 'N')
                --N_BLUE;
            else if (S[M - 1] == 'C')
                --N_RED;
            else if (S[M - 1] == 'Z')
                --N_GREEN;
        }
        else{
            if (S[M - 1] == 'N')
                --P_BLUE;
            else if (S[M - 1] == 'C')
                --P_RED;
            else if (S[M - 1] == 'Z')
                --P_GREEN;
        }
        S[M - 1] = C;
        std::cout << F() << '\n';
   }

    return 0;
}