#include<fstream>
#define MAXN 100005
#define LL long long
using namespace std;
ifstream cin("stergeri.in");
ofstream cout("stergeri.out");
int N,M,K;
LL A[MAXN],B[MAXN];
int main() {
	   int i;
 	   cin>>N>>M>>K;
	   for(i=1;i<=M;i++)
	      cin>>A[i]>>B[i];
	   for(i=M;i>=1;i--)
	         if(K>=A[i]) K+=(B[i]-A[i]+1);
cout<<K;
return 0;
}