/*
TASK:move
LANG:C++
*/
#include <iostream>

using namespace std;

int main()
{
    int i,j,k,l,n,m,br;
    
    cin>>n>>m; br=n+m;
    for (i=0; i<m; i++) { cin>>j>>k; br+=j*k; }
    for (i=0; i<n; i++) { cin>>l; br+=l; }
    br--;
    
    cout<<br%3-1<<"\n";
    
    return 0;
}
