#include <stdio.h>

#define in "stergeri.in"
#define out "stergeri.out"

#define dim 100001

int M, N, K;
int C[2][dim];

int main()
{
    freopen(in,"r",stdin);
    freopen(out,"w",stdout);
    
    scanf("%d%d%d", &N, &M, &K);
    for ( int i = M; i >= 1; i-- )
        scanf("%d%d", &C[0][i], &C[1][i]);
    
    for ( int i = 1; i <= M; i++ )
    {
        if ( K >= C[0][i] ) K += ( C[1][i] - C[0][i] + 1 );
    }
    
    printf("%d", K);
}