Local organizers of Sunday's Hands Across America "megacharity," faced with a sudden surge of contributors who want to join the coast-to-coast event, said yesterday that people without tickets should just show up where they want along the route.

The Washington office has started making direct assignments on its 29-mile segment of the 4,100-mile Hands Across America line and was distributing tickets for the route at a downtown promotional rally yesterday. But with the event only four days off, District, Maryland and Virginia residents who want to participate are being advised to pick their spots.

"Unfortunately, a lot of people have waited until the last minute to sign up, and we can't possibly process all the requests," said Judy Zack, a spokeswoman for Hands Across America's Maryland office. "We're encouraging them to show up, and we'll take their pledges that day."

Zack, whose office has turned to its counterpart in the District for help in assigning spots along Hands Across America's 156-mile route in Maryland, said she has no idea how many people have signed up to be on line in the state -- or where. Assignments are being made from so many quarters, she said, that Hands Across America will not know where the gaps in the line are until this weekend and will use radio stations Sunday to announce where people are most needed along the route.

A Hands Across America spokesman in Los Angeles said Monday that the number of people signed up nationwide for the event -- organized to benefit the homeless and hungry in the United States and costing $10 to $35 per participant -- is "2.5 million and growing by the hour."

But the apparent last-minute deluge of prospective hand holders, long predicted by organizers, is taxing many of Hands Across America's regional offices.

"We're getting calls from all over the South," said Donna Brazile, who runs Hands Across America's District office. Much of the South is outside the route, and residents there are being assigned to places.

Though popular spots on the Mall were filled some time ago, Brazile said there are still small gaps in the Southeast and Georgetown "feeder routes." Also, the Embassy Row section of Massachusetts Avenue NW has been especially hard to fill because, for security reasons, only individuals, not corporate sponsors or organized groups, will be permitted in front of embassies.

The District Hands Across America office held its last promotional event yesterday at Connecticut Avenue and L Street NW, accepting an enlarged check for $35,000 from First American Bank, a major local sponsor of the event. Employes and their families from the bank's various area branches have purchased more than 2,600 spots around the Washington Monument. They will be sharing what they call "the most patriotic mile" on the route with Olympic gymnast Mary Lou Retton, one of several sports and entertainment celebrities expected to join the line in Washington.

The bank organized an AmeriCAN drive to promote Hands Across America, collecting more than 15,000 cans of food at its branches for distribution to Salvation Army programs here. The food drive continues through this week.

"This is the first thing we've done for the hungry and homeless involving all our bank branches," said Eric Erdossy, executive vice president of First American, who said he expected the bank to stay involved in the issue.

Also yesterday, Hands Across America here released a list of 16 staging areas and checkpoints along the route, including Dupont Circle, Hechinger Mall in Northeast and Malcolm Martin Marcus Park at 14th and V streets SE, where participants can gather, see live entertainment, purchase tickets, get information and find first aid and water.