Using "#define" in pair<>!!
  main.cpp         main.cpp    TO quickly type we can use #define in pair like this :    #define pii pair< int , int >  #define ppi pair<pii , int >  #define ppp pair<pii , pii>  #define ss second  #define ff first    CODE:    #include <bits/stdc++.h> using namespace std ; #define ll long long #define pii pair< int , int >  #define ppi pair<pii , int >  #define ppp pair<pii , pii>  #define ss second  #define ff first    int main()  {      pii p1 ;       ppi p2 ;       cin>>p1.ff>>p1.ss ;       p2=ppi(p1 , p1.ss*p1.ff) ;       cout<< "Entry: " <<p2.ff.ff<< " , " <<p2.ff.ss<<endl ;       cout<< "Product: " <<p2.ss<<endl ;    return 0 ;   }