#include <cstdio>

struct pozitie
{
    int a;
    int b;
};

pozitie v[100001];

using namespace std;

int main()
{
    freopen( "stergeri.in", "r", stdin );
    freopen( "stergeri.out", "w", stdout );

    int n, m, i, k, x, y;

    scanf( "%d%d%d", &n, &m, &k );

    for( i=1;i<=m;i++ )
        scanf( "%d%d", &v[i].a, &v[i].b );

    for( i=m;i>=1;i-- )
        if( v[i].a<=k )
            k+=v[i].b-v[i].a+1;

    printf( "%d", k );

    return 0;
}