foo.cc: In function 'll fy(int, int, int)':
foo.cc:27:23: warning: for increment expression has no effect [-Wunused-value]
     for (int i=1;i<=n;i){
                       ^
foo.cc: In function 'int main()':
foo.cc:36:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d",&n,&m);
     ~~~~~^~~~~~~~~~~~~~

正在同步测试数据，请稍后
自豪的采用HydroJudge(https://github.com/hydro-dev/Hydro)进行评测。