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//
#ifndef __SIZEOF_INT128__
#define __SIZEOF_INT128__
#endif
#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/priority_queue.hpp>
using namespace std;
using namespace chrono;
using namespace __gnu_pbds;
template <typename T> using oset =  tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define rep(i, p, k) for(int i(p); i < k; ++i)
#define per(i, p, k) for(int i(p); i > k; --i)
#define sz(x) (int)x.size()
#define sc static_cast
typedef long long ll;
typedef long double ld;
typedef unsigned int uint;
typedef unsigned long long ull;
typedef __int128_t lll;
//#define int ll
template <typename T = int> using par = std::pair <T, T>;
#define fir first
#define sec second
#define test int _number_of_tests(in()); while(_number_of_tests--)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define pb emplace_back
struct Timer {
    string name{""};
    time_point<high_resolution_clock> end, start{high_resolution_clock::now()};
    duration<float, std::milli> dur;
    Timer() = default;
    Timer(string name): name(name) {}
    ~Timer() {
        end = high_resolution_clock::now(); dur= end - start;
        cout << "@" << name << "> " << dur.count() << " ms" << '\n';
    }
};
template <typename T = int> inline T in()
{
    T x;
    std::cin >> x;
    return x;
}
std::string yn(bool b)
{
    if(b) return "YES\n";
    else return "NO\n";
}
template <typename F, typename S> std::ostream& operator<<(std::ostream& out, const std::pair <F, S>& par);
template <typename T> std::ostream& operator<< (std::ostream& out, const std::vector <T>& wek)
{
    for(const auto& i : wek)out << i << ' ';
    return out;
}
template <typename F, typename S> std::ostream& operator<<(std::ostream& out, const std::pair <F, S>& par)
{
    out << '{'<<par.first<<", "<<par.second<<"}";
    return out;
}
#define show(x) cout << #x << " = " << x << '\n';
constexpr int maxn = 2e5 + 3, mod = 1e9 + 7;
array <int, maxn> pc, pp[2];
char tab[maxn];
int odp(int cn, int cc, bool k0, bool k1, int r)
{
    if(r == 1)return 1 + !!cn;
    r = r%2;
    cc = (3 + cc) % 3;
    return (mod + pc[cn] - pp[!!cc][cn] - (r&&!k0) - (r&&!k1)) % mod;
}
inline bool kloc(int g, char c, bool z)
{
    return c != 'N' && ((c == 'C') == g%2) == z;
}
std::int32_t main()
{
    pc[0] = pp[0][0] = 1;
    pp[1][0] = 0;
    rep(i, 1, maxn){
        pp[0][i] = 2*pp[1][i-1] % mod;
        pp[1][i] = (pp[0][i-1] + pp[1][i-1]) % mod;
        pc[i] = 2*pc[i-1] % mod;
    }
    std::cin.tie(nullptr); std::cout.tie(nullptr); std::ios_base::sync_with_stdio(0);
    int n(in()), q(in());
    rep(i, 1, n+1)cin >> tab[i];
    int cn(0), cc(0), k[2]{};
    rep(i, 1, n+1){
        cn += tab[i] == 'N';
        cc -= tab[i] == 'Z';
        cc += tab[i] == 'C';
        k[0] += kloc(i, tab[i], 0);
        k[1] += kloc(i, tab[i], 1);
    }
    cout << odp(cn, cc, k[0], k[1], n) << '\n';
    while(q--){
        int g(in());
        char c(in<char>());
        cn -= tab[g] == 'N';
        cc += tab[g] == 'Z';
        cc -= tab[g] == 'C';
        k[0] -= kloc(g, tab[g], 0);
        k[1] -= kloc(g, tab[g], 1);
        cn += c == 'N';
        cc -= c == 'Z';
        cc += c == 'C';
        k[0] += kloc(g, c, 0);
        k[1] += kloc(g, c, 1);
        tab[g] = c;
        cout << odp(cn, cc, k[0], k[1], n) << '\n';
    }
    return 0;
}