modinveersse

ll modularExponentiation(ll x,ll n,ll M)
{
    ll result=1;
    while(n>0)
    {
        if(n % 2 ==1)
            result=(result * x)%M;
        x=(x*x)%M;
        n=n/2;
    }
    return result;
}
ll modinv(ll A)
{
    return modularExponentiation(A,m-2,m);
}