Tens of thousands of people on Sunday protested the skyrocketing cost of living that they blame on government reforms to liberalize the economy. The protest by trade unionists in Constantine, this North African country's third-largest city, came two years after economic riots swept the nation. ``That's enough, the poor are dying,'' the protesters cried, brandishing empty food baskets, as they marched through the streets of Constantine, 300 miles east of the capital. The crowd presented a list of its grievances at regional government offices and in a letter to President Chadli Bendjedid, Algerian TV reported. They demanded lower food prices and job protection. Bendjedid introduced sweeping economic and political reforms in Algeria after the riots in October 1988, where army troops gunned down scores of Algerians protesting declining living standards. But market reforms are coming slowly and sales of Algeria's principal export, oil, have been unable to revitalize a stagnant economy marked by official unemployment of 25 percent.