#include<stdio.h>
#define Nmax 1000001
FILE *f=fopen("stergeri.in","r");
FILE *g=fopen("stergeri.out","w");

long long n,m,x,a[Nmax],b[Nmax];

int main()
{

fscanf(f,"%lld%lld%lld",&n,&m,&x);



 for(long i=1;i<=m;i++)
   fscanf(f,"%lld%lld",&a[i],&b[i]);
    
 for(long i=m;i>=1;i--)
   if(a[i]<=x)
    x+=b[i]-a[i]+1;
        
        

    fprintf(g,"%lld",x);
   fcloseall();

return 0;

}