new_contents: 
  class uf:
      def __init__(self):
          self.parent = {}
          self.rank = {}
  
      def find(self, x):
          if x not in self.parent:
              self.parent[x] = x
              self.rank[x] = 0
              return x
          xp = self.parent[x]
          if xp != x:
              self.parent[x] = self.find(xp)
          return self.parent[x]
  
      def union(self, x, y):
          xr = self.find(x)
          yr = self.find(y)
  
          if xr == yr:
              return
  
          if self.rank[xr] < self.rank[yr]:
              self.parent[xr] = yr
          elif self.rank[xr] > self.rank[yr]:
              self.parent[yr] = xr
          else:
              self.parent[yr] = xr
              self.rank[xr] += 1
  
  
subject: Add missing file