#include <cstdio>

int N,M,K;

struct {int li, lf;} m[100001];

void solve()
{
  for(int i=M; i; i--)
    if(m[i-1].li <= K)
      K+= (m[i-1].lf - m[i-1].li + 1);
      
  printf("%d\n",K);
}

int main()
{
  freopen("stergeri.in","r",stdin);
  freopen("stergeri.out","w",stdout);
  
  scanf("%d %d %d",&N,&M,&K);
  
  for(int i=0; i<M; i++)
    scanf("%d %d",&m[i].li,&m[i].lf);
    
  solve();
}