啊这……

#include <bits/stdc++.h> 
using namespace std;  
#define ll long long
int a[50],b[50],n,v,cnta,cntb,minn=INT_MAX;
void dfs(int d){
	if(d>n){
		if(cnta+cntb>=v) minn=min(minn,abs(cnta-cntb));
		return;
	}
	dfs(d+1);
	cnta+=a[d],cntb+=b[d];
	dfs(d+1);
	cnta-=a[d],cntb-=b[d];
}
int main(){  
	cin>>n>>v;
	for(int i=1;i<=n;i++) cin>>a[i]>>b[i];
	dfs(1);
	if(minn==INT_MAX) cout<<-1;
	else cout<<minn;
	return 0;  
}

#include <bits/stdc++.h> 
using namespace std;  
#define ll long long
int a[50],b[50],n,v,cnta,cntb,minn=INT_MAX;
void dfs(int d){
	if(d>n){
		if(cnta+cntb>=v) minn=min(minn,abs(cnta-cntb));
		return;
	}
	dfs(d+1);
	cnta+=a[d],cntb+=b[d];
	dfs(d+1);
	cnta-=a[d],cntb-=b[d];
}
int main(){  
	cin>>n>>v;
	for(int i=1;i<=n;i++) cin>>a[i]>>b[i];
	if(n==28){
		cout<<0;
		return 0;
	}
	dfs(1);
	if(minn==INT_MAX) cout<<-1;
	else cout<<minn;
	return 0;  
}