# include <fstream>
# define DIM 100010
using namespace std;
ifstream fin("stergeri.in");
ofstream fout("stergeri.out");
int st[DIM],dr[DIM],i,j,n,m,k;
int main () {
    fin>>n>>m>>k;
    for(i=1;i<=m;i++)
        fin>>st[i]>>dr[i];
    for(i=m;i>=1;i--){
        if(k>=st[i])
            k+=dr[i]-st[i]+1;
    }
    fout<<k<<"\n";
    return 0;
}