extented euclid

ll d, x, y;
void extendedEuclid(ll A, ll B) {
    if(B == 0) {
        d = A;
        x = 1;
        y = 0;
    }
    else {
        extendedEuclid(B, A%B);
        ll temp = x;
        x = y;
        y = temp - (A/B)*y;
    }
}
ll modinv(ll a){
   extendedEuclid(a,m);
    return (x%m+m)%m;
}