#include <fstream>
using namespace std;

ifstream in("lapte.in");
ofstream out("lapte.out");

int bs()
{
    int i,pas=1<<16;
    for(i=1;i<=n;pas<<=1)
    {
        if(i+pas<=n && ok(i+pas))
            i+=pas;
    }
    return i;
}
int main()
{
    in>>n>>l;
    for(i=1;i<=n;i++)
        in>>a[i]>>b[i];

    out<<bs()<<"\n";

    return 0;
}