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#include <bits/stdc++.h>

using namespace std;

typedef unsigned uint;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ldbl;
typedef pair<int, int> pii;
typedef pair<uint, uint> puu;
typedef pair<ll, ll> pll;
typedef pair<ull, ull> pull;
typedef pair<double, double> pdd;
typedef vector<int> vi;
typedef vector<uint> vu;
typedef vector<ll> vll;
typedef vector<ull> vull;
typedef vector<pii> vpii;
typedef vector<puu> vpuu;
typedef vector<pll> vpll;
typedef vector<pull> vpull;
typedef vector<string> vstr;
typedef vector<double> vdbl;
typedef vector<ldbl> vldbl;
#define pb push_back
#define ppb pop_back
#define pfr push_front
#define ppfr pop_front
#define emp emplace
#define empb emplace_back
#define be begin
#define rbe rbegin
#define all(x) (x).be(), (x).end()
#define rall(x) (x).rbe(), (x).rend()
#define fir first
#define sec second
#define mkp make_pair
#define brif(cond) if (cond) break
#define ctif(cond) if (cond) continue
#define retif(cond) if (cond) return
void canhazfast() {ios_base::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr);}
template<typename T> T gcd(T a, T b) {return b ? gcd(b, a%b) : a;}
template<typename T> T extgcd(T a, T b, T &x, T &y)
{
    T x0 = 1, y0 = 0, x1 = 0, y1 = 1;
    while (b) {
        T q = a/b; a %= b; swap(a, b);
        x0 -= q*x1; swap(x0, x1);
        y0 -= q*y1; swap(y0, y1);
    }
    x = x0; y = y0; return a;
}
int ctz(uint x) {return __builtin_ctz(x);}
int ctzll(ull x) {return __builtin_ctzll(x);}
int clz(uint x) {return __builtin_clz(x);}
int clzll(ull x) {return __builtin_clzll(x);}
int popcnt(uint x) {return __builtin_popcount(x);}
int popcntll(ull x) {return __builtin_popcountll(x);}
int bsr(uint x) {return 31^clz(x);}
int bsrll(ull x) {return 63^clzll(x);}

#define MOD 1000000007

uint add(uint a, uint b) { return a+b < MOD ? a+b : a+b-MOD; }
uint sub(uint a, uint b) { return a < b ? a+MOD-b : a-b; }
uint mul(uint a, uint b) { return (ull)a*b%MOD; }
uint sqr(uint a) { return mul(a, a); }

uint modpow(uint b, uint e)
{
    uint r = 1;
    for (; e; e >>= 1) {
        if (e&1) r = mul(r, b);
        b = sqr(b);
    }
    return r;
}

uint modpowll(uint b, ull e)
{
    uint r = 1;
    for (; e; e >>= 1) {
        if (e&1) r = mul(r, b);
        b = sqr(b);
    }
    return r;
}

uint modinv(uint n) { return modpow(n, MOD-2); }
uint moddiv(uint n, uint d) { return mul(n, modinv(d)); }

int lookup(char c)
{
    switch (c) {
    case 'N':
        return 0;
    case 'C':
        return 1;
    case 'Z':
        return 2;
    }
    return -1;
}

#define N 200016
#define Q 100016

int f[2][3]; /// i%2, N|C|Z
char s[N];
int dp[N][2]; /// cnt, nz
int a[N];

void put_elem(int i)
{
    ++f[i%2][a[i]];
}

void del_elem(int i)
{
    --f[i%2][a[i]];
}

uint calc(bool odd)
{
    int sum = (2*(f[0][2]+f[1][2])+f[0][1]+f[1][1])%3;
    int fn = f[0][0]+f[1][0];
    ///uint res = sum ? add(dp[fn][0], dp[fn][1]) : mul(dp[fn][1], 2);
    /// equiv:
    uint res = dp[fn+1][sum!=0];
    if (odd) {
        if (f[0][2] == 0 && f[1][1] == 0) res = sub(res, 1);
        if (f[0][1] == 0 && f[1][2] == 0) res = sub(res, 1);
    }
    return res;
}

int main()
{
    canhazfast();

    int n, q;

    cin >> n >> q >> s;
    dp[0][0] = 1;
    for (int i = 0; i <= n; ++i) {
        dp[i+1][0] = mul(dp[i][1], 2);
        dp[i+1][1] = add(dp[i][0], dp[i][1]);
    }
    for (int i = 0; i < n; ++i) {
        a[i] = lookup(s[i]);
        put_elem(i);
    }
    cout << calc(n%2) << '\n';
    for (int i = 0; i < q; ++i) {
        int k;
        char c;
        cin >> k >> c;
        --k;
        del_elem(k);
        a[k] = lookup(c);
        put_elem(k);
        cout << calc(n%2) << '\n';
    }

    return 0;
}