foo.cc: In function 'void ex(long long int)':
foo.cc:12:10: warning: unused variable 'k' [-Wunused-variable]
  int i,j,k,l=s[num].size();
          ^
foo.cc: In function 'int main()':
foo.cc:122:11: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   while(ch=getchar()){
         ~~^~~~~~~~~~
foo.cc:105:8: warning: unused variable 'j' [-Wunused-variable]
  int i,j,k,x,y;
        ^
foo.cc:105:10: warning: unused variable 'k' [-Wunused-variable]
  int i,j,k,x,y;
          ^
foo.cc:105:12: warning: unused variable 'x' [-Wunused-variable]
  int i,j,k,x,y;
            ^
foo.cc:105:14: warning: unused variable 'y' [-Wunused-variable]
  int i,j,k,x,y;
              ^
foo.cc: In function 'bool check()':
foo.cc:75:3: warning: 'k' may be used uninitialized in this function [-Wmaybe-uninitialized]
   if(k^really[tk[i]])return 0;
   ^~

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