中国剩余定理

LL china(int n, int* a, int *m){
    LL M=1, d, y, x = 0;
    for(int i = 0; i < n; i++) M *= m[i];
    for(int i = 0; i < n; i++) {
        LL w = M / m[i];
        gcd(m[i], w, d, d, y);
        x = (x + y*w*a[i])%M;
    }
    return (x+M)%M;
}