Pope John Paul has marked the 24th anniversary of the start of his papacy by praying for strength. The 82-year-old pontiff is asking the Virgin Mary to help him continue his mission. Tens of thousands of pilgrims cheered, waved Polish flags and held up white handkerchiefs as the pope was driven into St. Peter's Square. John Paul is one of the longest-serving popes -- outliving many of his possible successors. He's repeatedly brushed aside reports he might step down. The pope also announced additions to the Rosary -- a series of prayers, many dedicated to Mary, that are said over and over on a string of beads. John Paul says Roman Catholics should contemplate Jesus's baptism, miracles and institution of Communion when they recite the Rosary.