/in/foo.c: In function 'main':
/in/foo.c:13:12: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   if(c>='a'&&c<='z'||c>='A'&&c<='Z') word[pos]=c,pos++;
      ~~~~~~^~~~~~~~
/in/foo.c: In function 'find':
/in/foo.c:29:51: error: 'sum' undeclared (first use in this function)
  if(!flag&&strlen(b)) printf("%s",b),strcpy(words[sum],b),cnt++;
                                                   ^~~
/in/foo.c:29:51: note: each undeclared identifier is reported only once for each function it appears in
/in/foo.c:29:58: warning: left-hand operand of comma expression has no effect [-Wunused-value]
  if(!flag&&strlen(b)) printf("%s",b),strcpy(words[sum],b),cnt++;
                                                          ^