#include <bits/stdc++.h>
using namespace std;
#define int long long
#define pii pair<int,int>
#define pb push_back
#define all(x) x.begin(),x.end()
#define ff first
#define ss second
signed main(){
ios_base::sync_with_stdio(false);cin.tie(0);
int n, m;cin>>n>>m;
int tmp=0;
vector<int> x(n), y(n);
vector<bool> inv(n, 0);
for(int i=0; i<n; i++) cin>>x[i]>>y[i];
for(int i=1; i<n-2; i++){
if(x[i]==x[i-1]&&x[i]==x[i+1]) inv[i]=1;
if(y[i]==y[i-1]&&y[i]==y[i+1]) inv[i]=1;
}
for(int i=0; i<n-1; i++){
if(inv[i]) continue;
if((x[i]%2)||(y[i]%2)){
cout<<tmp;
break;
}else{
tmp=x[i];
}
}
cout<<tmp;
}
