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class CDateTime
{
public:
    int year,mon,day,hour,min,sec,MDay;
    CDateTime();
    CDateTime(int y,int m,int d,int h,int mi,int s);
    void operator = (const string str);
    void operator = (const CDateTime &x);
    int operator [] (const string str);
    friend long long int operator - (const CDateTime &x,const CDateTime &y);
    friend CDateTime operator + (const CDateTime &x,long long int y);
    friend bool operator == (const CDateTime &x,const CDateTime &y);
    friend bool operator != (const CDateTime &x,const CDateTime &y);
    friend bool operator >= (const CDateTime &x,const CDateTime &y);
    friend bool operator <= (const CDateTime &x,const CDateTime &y);
    friend bool operator > (const CDateTime &x,const CDateTime &y);
    friend bool operator < (const CDateTime &x,const CDateTime &y);
    friend ostream & operator << (ostream &os,const CDateTime &x);
    friend bool DCheck(int y,int m,int d,int h,int mi,int s);
    friend int MDays(int y,int m);
    friend string IToS(int a);
    friend char IToC(int num);
    friend int CToI(char ch);
    friend long long int Odec(const CDateTime &x,const CDateTime &y);
};