#include <cstdio>
#define NMax 100000

int n, max, c[NMax], e[NMax], a[NMax];

int main()
{
	int i, j, aux, aux2=-100, poz;
	FILE *fin = fopen( "energii.in", "rt" );
	fscanf( fin, "%d %d", &n, &max );
	for (i=0; i<n; i++)
		fscanf( fin, "%d %d", &e[i], &c[i] );

	a[0] = 0;
	for (i=1; i<=n; i++)
	{
		for (j=i; j>0; j--)
		{
			aux = e[j] + a[i-c[j]];
			if ( aux > aux2 )
			{
				aux2 = aux;
				poz = i;
			}
		}
		a[i] = aux2;
	}

	FILE *fout = fopen( "energii.out", "wt" );
	fprintf( fout, "%d", c[poz] );

	return 0;
}