#include <stdio.h>

int v[200002];
int n,m,k,i;

int main ()
{
    freopen ("stergeri.in","r",stdin);
    freopen ("stergeri.out","w",stdout);
    
    scanf ("%d %d %d",&n,&m,&k);
    for (i=1;i<=2*m+1;i=i+2) scanf ("%d %d",&v[i],&v[i+1]);
    
    for (i=2*m;i>0;i=i-2)
        if (k>=v[i-1]) k=k+v[i]-v[i-1]+1;
        
    printf ("%d",k);

    
    return 0;
}