NEW YORK — The nation’s largest school system lurched to life Monday, with all but the students most affected by Superstorm Sandy making their way back to classes on foot, ferry and subway.

Students at Stuyvesant High School, the city’s most selective school, swarmed out of Lower Manhattan’s subway stations after electricity was restored to the devastated area by the weekend.

“Being cooped up in my house for nine days was not fun!” said sophomore Nathan Mannes. “I did my homework, and when I finished that I played some video games.”

Less than 50 schools throughout the five boroughs remained closed because of structural damage and fewer than 20 were without power, Mayor Michael Bloomberg told reporters at mid-day. About 16 were being used to shelter people left homeless by Sandy, though most will be relocated by the time those students return Wednesday, he said.