foo.cc: In function 'll ksm(ll, ll)':
foo.cc:14:9: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
         if(s&1) ds=(ds*ft)%mod;
         ^~
foo.cc:15:3: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
   s>>=1;ft=(ft*ft)%mod;
   ^
foo.cc: In function 'int main()':
foo.cc:22:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%lld",&n);
  ~~~~~^~~~~~~~~~~

自豪的采用HydroJudge(https://github.com/hydro-dev/Hydro)进行评测。