백준 2292 : 벌집

 

 

#include <stdio.h>

int main() {
   int cnt=0, room = 0;
   int total = 1;
   scanf("%d", &room);

   while(1) {
      total += 6*cnt;
      if(room <= total)
         break;
      cnt++;
   }

   printf("%d\n", cnt+1);
   return 0;
}