#include <iostream>
#include <fstream>
using namespace std;

int main()
{
int x[100000],y[100000],i,m,q=1;
long long n,sol,k;

fstream f,g;
f.open("stergeri.in",ios::in);
g.open("stergeri.out",ios::out);
f>>n;
f>>m;
f>>k;

while(f>>x[q] && f>>y[q])
    q++;

for(i=m;i>=1;i--){
        if(k>=x[i])
            k=k+(y[i]-x[i]+1);
}
sol=k;
g<<sol;}