#include "bits/stdc++.h"
using namespace std;

#define FAST ios_base::sync_with_stdio(false); cin.tie(0);
#define pb push_back
#define eb emplace_back
#define ins insert
#define f first
#define s second
#define cbr cerr << "hi\n"
#define mmst(x, v) memset((x), v, sizeof ((x)))
#define siz(x) ll(x.size())
#define all(x) (x).begin(), (x).end()
#define lbd(x,y) (lower_bound(all(x),y)-x.begin())
#define ubd(x,y) (upper_bound(all(x),y)-x.begin())
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());    //can be used by calling rng() or shuffle(A, A+n, rng)
inline long long rand(long long x, long long y) { return (rng() % (y+1-x)) + x; } //inclusivesss
string inline to_string(char c) {string s(1,c);return s;} template<typename T> inline T gcd(T a,T b){ return a==0?llabs(b):gcd(b%a,a); }

typedef long long ll; 
typedef long double ld;
#define FOR(i,s,e) for(ll i=s;i<=ll(e);++i)
#define DEC(i,s,e) for(ll i=s;i>=ll(e);--i)
typedef pair<ll,ll>pi; typedef pair<ll,pi>spi; typedef pair<pi,pi>dpi;

#define LLINF ((long long)1e18)
#define INF int(1e9+1e6)
#define MAXN (200006)
ll n, m;
vector<pi>A;
bitset<MAXN> in, vis, val;
vector<pi> v[MAXN];
int main(){
	FAST
	cin>>n>>m;
	A.resize(n);
	FOR(i,0,n-1)cin>>A[i].f>>A[i].s;
	sort(all(A));
	A.eb(1e9+1, 0);
	FOR(i,0,n) {
		val[i] = (A[i].s&1) ^ ((i ? A[i-1].s : 0)&1); // here when 2 elements are different the right one differs instead
	}
	FOR(i,0,m-1){
		ll l, r; cin>>l>>r;
		l = lbd(A, pi(l,0));
		r = ubd(A, pi(r,LLINF));
		if(l==r) continue;
		v[l].eb(r,i), v[r].eb(l,i);
	}
	bool can=1;
	function<bool(ll)> dfs=[&](ll x){
		bool ret = val[x];
		vis[x]=1;
		for(auto i:v[x]) if(!vis[i.f]) {
			bool res = dfs(i.f);
			in[i.s] = res;
			ret ^= res;
		}
		return ret;
	};
	FOR(i,0,n) if(!vis[i]) {
		can &= !dfs(i);
	}
	if(can){
		cout<<in.count()<<'\n';
		FOR(i,0,m-1) if(in[i]) cout<<i+1<<' ';
		cout<<'\n';
	}else{
		cout<<"-1\n";
	}
}
