/**
 * with the help of God
 */
#include <iostream>
#include <cstdio>
#include <set>
#include <queue>
#include <stack>
#include <cstdlib>
#include <cstring>
#include <climits>
#include <cmath>
#include <deque>
#include <algorithm>
#include <vector>
#include <cassert>
#include <fstream>
#include <sstream>
#include <iomanip>
#include <list>
#include <complex>
#include <functional>

using namespace std;

//typedef

typedef long long ll;
typedef long double ld;
typedef unsigned int ui;
typedef unsigned long long ull;
typedef pair<int,int> pii;

//define

#define gi ({int t; scanf("%d",&t); t;})
#define gl ({ll t; scanf("%lld",&t); t;})
#define gd ({double t;scanf("%lf",&t); t;})
#define rep(i,n) for(int i=0,_n=n;i<_n;i++)
#define fr(i,a,b) for(int i=a;i<b;i++)
#define frd(i,a,b)  for(int i=b;i>=a;i--)
#define repd(i,n) for(int _n=n,i=_n-1;i>=0;--i)
#define fit(i,v) for(__typeof((v).begin()) i =(v).begin(); i != (v).end(); ++i)
#define fitd(i,v) for(__typeof((v).rbegin()) i=(v).rbegin(); i!=(v).rend();++i)
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define ms(a,x) memset(a, x, sizeof(a))
#define sz(c) (int)(c).size()
#define dbg(x) cerr<<#x<<" = "<<(x)<<endl
#define sqr(x) ((x)*(x))
#define mod (ll) (1e4 + 7 + eps)
#define READ(f) freopen(f, "r", stdin)
#define WRITE(f) freopen(f, "w", stdout)


// maximum subarray sum
void mss(int* a, int n, int x){
    rep(i,n){
        if(a[i] >= x){ printf("1\n"); return; }
    }
    ll s[n];
    deque <pii> dq;
    s[0] = a[0];
    ll cmx = a[0]; // current maximum
    int st[n];
    int start = 0;
    st[0] = 0; // start point from where cmx is calculated
    fr(i,1,n){
        cmx = max(cmx+a[i],(ll)a[i]);
        if(cmx == a[i]) start = i;
        s[i] = cmx;
        st[i] = start;
    }
    int mi = (1<<30)-1;
    ll sp = 0; // sum of popped elements
    rep(i,n){
        while(dq.size() > 0 && dq[0].second < st[i]){ sp = 0; dq.pop_front(); }
        ll ele = s[i]-sp;
        dq.pb(pii(a[i],i));
        if(ele < x) continue;
        while(dq.size() > 0 && ele-dq[0].first >= x){
            sp+=dq[0].first;
                ele-=dq[0].first;
            dq.pop_front();
        }
        mi = min(mi, sz(dq));
    }
    if(mi == (1<<30)-1) printf("-1\n");
    else printf("%d\n",mi);
}

void main2(){
    int n, x;
    n = gi, x = gi;
    int a[n];
    rep(i,n){
        a[i] = gi;
    }
    mss(a,n,x);
}

int main(){
    int t;
    t = gi;
    while(t--) main2();
}