ll@n,@q,x[n+1],c[n+1];
x[0]=0,c[0]=0;
rep(i,n){ll@a;x[i+1]=x[i]+a;c[i+1]=c[i]+a*(a+1)/2;}
rep(q){ll@s;if(c[n]<s){wt(-1);}else{
		ll l = lower_bound(c, c + n + 1, s) - c;
		wt(x[l-1]+int(sqrt(2*(s-c[l-1]))+.5));
	}
}