Given the task definition, example input & output, solve the new input case.
Given a question and a context passage, generate the answer having the word or phrase from the context passage. Here, the answer should be a shortest continous span from the passage.
Example: Context: Architecturally, the school has a Catholic character. Atop the Main Building's gold dome is a golden statue of the Virgin Mary. Immediately in front of the Main Building and facing it, is a copper statue of Christ with arms upraised with the legend 'Venite Ad Me Omnes'. Next to the Main Building is the Basilica of the Sacred Heart. Immediately behind the basilica is the Grotto, a Marian place of prayer and reflection. It is a replica of the grotto at Lourdes, France where the Virgin Mary reputedly appeared to Saint Bernadette Soubirous in 1858. At the end of the main drive (and in a direct line that connects through 3 statues and the Gold Dome), is a simple, modern stone statue of Mary.
Question: To whom did the Virgin Mary allegedly appear in 1858 in Lourdes France?
Output: Saint Bernadette Soubirous
This is the correct answer. Because the question is asking for the name of the person and following sentence from the passage answers it: It is a replica of the grotto at Lourdes, France where the Virgin Mary reputedly appeared to Saint Bernadette Soubirous in 1858.

New input case for you: Context: The proto-oncogene ras is an essential gene for the growth and the differentiation for various types of cells. Ras, ras gene product, is a GTP binding protein which controls the signal transduction by GTP hydrolysis. The ras gene is frequently activated by point mutations in various types of human cancers, which results in a decrease in the GTPase activity of its product. A GTPase-activating protein p120 (p120GAP) was identified as a factor which stimulates the GTPase of normal ras gene product p21 but not of the mutated. An NF1 gene was identified as a gene whose loss of function causes an onset of human disorder, neurofibromatosis type I. The NF1 gene encodes a protein which contains a region with a similarity to the catalytic domain of p120GAP. We recently purified a novel Ras GAP whose molecular weight and immunogenecity are different from those of p120GAP and NF1. We named the novel mammalian Ras GAP as Gap1m. Isolation and sequencing of Gap1m cDNA revealed that Gap1m is indeed a novel Ras GAP. We also succeeded in isolation of another novel Ras GAP gene, GapIII/Gap1IP4BP, which is closely related to Gap1m. Recently, it is shown that GapIII/Gap1IP4BP binds inositol-tetrakis phosphate compounds. The overview of these Ras GAP molecules is described.
Question: Which is the gene mutated in type 1 neurofibromatosis?
Output:
nf1