foo.cc: In function 'int main()':
foo.cc:8:5: error: expected ';' before 'cout'
     cout<<(a+b+c)%3<<endl;
     ^~~~
foo.cc:10:5: error: expected ';' before 'if'
     if(b>a&&b>c) maxn=b
     ^~

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