#include<fstream>
using namespace std;
int n, m, k, i;
struct x2{
    int a;
    int b;
};
x2 x[100003];
ifstream in("stergeri.in");
ofstream out("stergeri.out");
int main(){
    in>>n>>m>>k;
    for(i=m; i>=1; i--)
        in>>x[i].a>>x[i].b;
    for(i=1; i<=m; i++)
        if(x[i].a<k)
            k+=x[i].b-x[i].a+1;
    out<<k;
return 0;
}