/in/foo.cc: In function 'void dfs(int)':
/in/foo.cc:29:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
 if(!used[i]&&dis(idx,i)<=4*r*r)
              ~~~~~~~~~~^~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:45:24: warning: format '%d' expects argument of type 'int*', but argument 2 has type 'll* {aka long long int*}' [-Wformat=]
 scanf("%d%d%d",&n,&h,&r);
                        ^
/in/foo.cc:45:24: warning: format '%d' expects argument of type 'int*', but argument 3 has type 'll* {aka long long int*}' [-Wformat=]
/in/foo.cc:45:24: warning: format '%d' expects argument of type 'int*', but argument 4 has type 'll* {aka long long int*}' [-Wformat=]