output_description: Print an integer representing the minimum number of minutes needed to make N
  pieces of takoyaki.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N X T
attempt: class UnionFind:
      def __init__(self, n):
          self.n = n
          self.parents = [-1] * n
  
      def find(self, x):
          if self.parents[x] < 0:
              return x
          else:
              self.parents[x] = self.find(self.parents[x])
              return self.parents[x]
  
      def union(self, x, y):
          x = self.find(x)
          y = self.find(y)
  
          if x == y:
              return
  
          if self.parents[x] > self.parents[y]:
              x, y = y, x
  
          self.parents[x] += self.parents[y]
          self.parents[y] = x
  
      def size(self, x):
          return -self.parents[self.find(x)]
  
      def same(self, x, y):
          return self.find(x) == self.find(y)
  
      def members(self, x):
          root = self.find(x)
          return [i for i in range(self.n) if self.find(i) == root]
  
      def roots(self):
          return [i for i, x in enumerate(self.parents) if x < 0]
  
      def group_count(self):
          return len(self.roots())
  
      def all_group_members(self):
          return {r: self.members(r) for r in self.roots()}
  
      def __str__(self):
          return "\n".join("{}: {}".format(r, self.members(r)) for r in self.roots())
  
  
  xkd = input().split()
  N = int(xkd[0])
  X = int(xkd[1])
  T = int(xkd[2])
  
  times = int(N / X)
  if N % X != 0:
      times += 1
  
  ans = T * times
  print(ans)
  
problem_description: Statement
  
  Takahashi loves takoyaki - a ball-shaped snack.
  
  With a takoyaki machine, he can make at most X pieces of takoyaki at a time,
  taking T minutes regardless of the number of pieces to make.
  
  How long does it take to make N takoyaki?
samples: [{"input": "20 12 6", "output": "12\n    \n\nHe can make 12 pieces of takoyaki in the first 6 minutes and 8 more in the\nnext 6 minutes, so he can make 20 in a total of 12 minutes.\n\nNote that being able to make 12 in 6 minutes does not mean he can make 2 in 1\nminute.\n\n* * *"}, {"input": "1000 1 1000", "output": "1000000\n    \n\nIt seems to take a long time to make this kind of takoyaki."}]