sem2_3

#include <stdio.h>

int main(int argc, char** argv)
{
 char c, prevc;
 int symbols_cnt[256];
 for(int i = 0; i != 256; ++i)
  symbols_cnt[i] = 0;
 while(c != EOF)
 {
  c = getchar();
  if((c != ' ') && (c != '\t') && (c != '\n') && (++symbols_cnt[c] >= 3))
  {
   putchar(c);
   prevc = c;
  }
  else if((prevc != ' ') && (prevc != '\t') && (prevc != '\n'))
  {
   putchar('\n');
   prevc = '\n';
  }
  
 }
 return 0;
}