Watching her blind aunt and uncle struggle to navigate the steep slopes and scant sidewalks of this hilly city, one Palestinian girl decided to reinvent the stick.

Armed with spare parts that are hard to find in the West Bank, Asil Abu Lil and two classmates patched together an obstacle-detecting cane that has won them a trip to San Jose, California, for Intel Corp.'s international youth science fair.

The three girls are the first Palestinians to participate in the prestigious event.

"Of course, I want to go to America, but this project is important for the blind and we want it to help them," Asil said.

Students from more than 50 countries will compete in next month's International Science and Engineering Fair, vying for the grand prize of $75,000.

The 14-year-old girls built the beeping walking stick for a class project at their United Nations-funded girls' school. The cane uses two infrared sensors, one front-facing and one in the tip of the cane, to detect obstacles and drop-offs. They did so despite difficulties in getting parts because of travel restrictions in the West Bank.

The students produced two prototypes after making multiple trips to Ramallah, about 45 minutes away and past two Israeli checkpoints, to scour electronics stores for proper circuits and sensors.

Although various types of "laser canes" have existed since the early 1970s, the girls' design resolves a fundamental flaw in previous models by detecting holes in the ground, said Mark Uslan, director of the American Federation of the Blind's technology division.

The cane beeps when it passes over a hole or steps going downward.

The United Nations Relief and Works Agency provides schooling to more than a quarter million children in Gaza and the West Bank, often in crowded schools that run two shifts of students a day.

"These girls are the Albert Einsteins of tomorrow," said Chris Gunness, a spokesman for the agency. "We need to teach the next generation rational thought, to think through problems and talk about problems. It's a microcosm of the peace process, if you like, and we need to spend time and invest in education because that is the peace dividend of tomorrow."

The girls beat dozens of contestants in the West Bank to win the prize. But even after that, they ran into one last obstacle: There was only enough prize money to allow two girls to make the trip. After drawing lots, Asil was to be left behind as her classmates headed to San Jose.

U.N. workers heard this and pooled money last week to purchase an additional ticket. When Asil heard the news on Monday, she broke into tears, leaping up from the table to embrace her classmates.

"Even when I'll be old, I will remember this time forever," Asil said.