foo.cc: In function 'int main()':
foo.cc:8:10: warning: format '%d' expects argument of type 'int*', but argument 2 has type 'll*' {aka 'long long int*'} [-Wformat=]
    8 |  scanf("%d %d",&n,&k);
      |         ~^     ~~
      |          |     |
      |          int*  ll* {aka long long int*}
      |         %lld
foo.cc:8:13: warning: format '%d' expects argument of type 'int*', but argument 3 has type 'll*' {aka 'long long int*'} [-Wformat=]
    8 |  scanf("%d %d",&n,&k);
      |            ~^     ~~
      |             |     |
      |             int*  ll* {aka long long int*}
      |            %lld
foo.cc:13:19: error: expression cannot be used as a function
   13 |   ans+=(x+y)(y-x+1)/2;
      |                   ^
foo.cc:8:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    8 |  scanf("%d %d",&n,&k);
      |  ~~~~~^~~~~~~~~~~~~~~

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