#include<iostream>
using namesapce std;
int main()
{
    int DD,MM,YYYY;
    cout<<"Enter the date: "<<endl;
    cin>>DD<<endl;
    cout<<"Enter the month:"<<endl;
    cin>>MM<<endl;
    cout<<"Enter the year:"<<endl;
    cin>>YYYY<<endl;
    if(1900<=YYYY=>2100,1<=MM=>12,1,=DD=>31)
    {
        cout<<YYYY"-"MM"-"DD<<endl;
    }
    else
    cout<<"invalid input"<<endl;
}