AC答案来啦

#include <iostream>
using namespace std;
int main(){
int a;
cin>>a;
a=(a+1)%7;
if(a1){
cout<<"monday"<<endl;
}else if(a2){
cout<<"tuesday"<<endl;
}else if(a3){
cout<<"wednesday"<<endl;
}else if(a4){
cout<<"thursday"<<endl;
}else if(a5){
cout<<"friday"<<endl;
}else if(a6){
cout<<"saturday"<<endl;
}else{
cout<<"sunday"<<endl;
}
return 0;