/in/foo.cc: In function 'void merge(int, int)':
/in/foo.cc:46:11: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int mid=l+r>>1;
          ~^~
/in/foo.cc: In function 'void calc(int, int)':
/in/foo.cc:82:11: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int mid=l+r>>1;
          ~^~
/in/foo.cc: In function 'void solve()':
/in/foo.cc:115:8: warning: unused variable 'j' [-Wunused-variable]
  int i,j,k;
        ^
/in/foo.cc:115:10: warning: unused variable 'k' [-Wunused-variable]
  int i,j,k;
          ^