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#include<bits/stdc++.h>

using namespace std;

typedef long long in;



void solve()
{
	in a,b,s;
	cin>>a>>b>>s;
	
	vector<pair<in,in>>v;
	for(int z=0;z<b;z++)
	{
		in k,l;
		cin>>k>>l;
		v.push_back({k,l});
	}
	
	sort(v.begin(),v.end());
	
	in zap;
	
	for(int z=0;z<b;z++)
	{
		if(v[z].first<=s&&v[z].second>=s)
		{
			zap=z;
		}
	}
	in k1;
	in k2;
	for(int z=zap;z<b;z++)
	{
		if(z==b-1||v[z].second!=v[z+1].first-1)
		{
			k1=v[z].second+1;
			break;
		}
	}
	for(int z=zap;z>=0;z--)
	{
		if(z==0||v[z].first!=v[z-1].second+1)
		{
			k2=v[z].first-1;
			break;
		}
	}
	if(k1==a+1)
	{
		cout<<k2;
		return;
	}
	if(k2==0)
	{
		cout<<k1;
		return;
	}
	
	if(s-k2<=k1-s)cout<<k2;else cout<<k1;
	
	
}


int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	
	int h=1;
	while(h--)solve();
	
	return 0;
}