#include <stdio.h>
#include <algorithm>

using namespace std;

long long n , m;
long long a[120000];
long long f;
long long mx;
void clear () {
    f = mx = 0;
}
long long go ( long long x ) {
    long long i;
    for ( i = 1 ; i <= n ; i++ ) {
        x += a[i];
        mx = max ( mx , x );
        if ( x < 0 ) x = 0;
        if ( x >= m ) {
            f = 1;
        }
    }
    return x;
}
void work () {
    long long i , x0 , x1 , x2;
    scanf ( "%lld%lld" , &n , &m );
    for ( i = 1 ; i <= n ; i++ ) {
        scanf ( "%lld" , &a[i] );
    }
    f = 0;
    x0 = go ( 0 );
    if ( f ) {
        printf ( "1\n" );
        return ;
    }
    x1 = go ( x0 );
    if ( f ) {
        printf ( "2\n" );
        return ;
    }
    //printf ( "%d %d\n" , x0 , x1 );
    if ( x1 == x0 ) {
        printf ( "-1\n" );
        return ;
    }
    x2 = go ( x1 );
    if ( f ) {
        printf ( "3\n" );
        return ;
    }
    printf ( "%lld\n" , 3 + (m-mx-1) / (x2-x1) + 1 );
}
int main () {
    int t;
    scanf ( "%d" , &t );
    while ( t-- ) {
        work ();
        clear ();
    }
    return 0;
}