#include<iostream>
#include<fstream>
using namespace std;
int a[100004],b[100005],i,n,m,j,k;
int main()
{

    ifstream cin("stergeri.in");
    ofstream cout("stergeri.out");
    cin>>n>>m>>k;
    for(i=1;i<=m;i++)
    {

        cin>>a[i]>>b[i];
    }
    for(i=m;i>=1;i--)
    {

        if(a[i]<=k)
            k+=b[i]-a[i]+1;

    }
    cout<<k;
    return 0;
}