#include<bits/stdc++.h>
#define rep(i, a, b) for(int i = (a); i < (b); i++)
#define _for(i, a, b) for(int i = (a); i <= (b); i++)
using namespace std;

const int N = (1 << 10) + 10;
bitset<N> f[N];
int n, m, w[N], v[N];

int main()
{
	int T; scanf("%d", &T);
	while(T--)
	{
		scanf("%d%d", &n, &m);
		_for(i, 1, n) scanf("%d%d", &v[i], &w[i]);

		rep(j, 0, 1 << 10)
			f[j].reset();

		f[0][0] = 1;
		_for(i, 1, n)
			rep(j, 0, 1 << 10)
				f[j] |= f[j ^ w[i]] << v[i];
		
		int ans = -1;
		for(int S = (1 << 10) - 1; S >= 0; S--)
			if(f[S][m])
			{
				ans = S;
				break;
			}
		printf("%d\n", ans);
	}

	return 0; 
}