how can i make the program loop instead of "press any key to continue"?

my calculator will not do this (it says main() is unidentified) in vc++

Code:#include <iostream.h> #include <conio.h> int ad() { cout<<"Enter two numbers to add:\n"; int x,y; cin>>x; cin>>y; cout<<"="<<x+y<<"\n"; return 0; } int subt() { cout<<"Enter two numbers to subtract:\n"; int x,y; cin>>x; cin>>y; cout<<"="<<x-y<<"\n"; return 0; } int divi() { cout<<"Enter two numbers to divide:\n"; int x,y; cin>>x; cin>>y; cout<<"="<<x/y<<"\n"; return 0; } int multi() { cout<<"Enter two numbers to multiply:\n"; int x,y; cin>>x; cin>>y; cout<<"="<<x*y<<"\n"; return 0; } int main() { cout<<"1: add\n"; cout<<"2: subtract\n"; cout<<"3: multiply\n"; cout<<"4: divide\n"; int input; cin>>input; switch (input) { case 1: ad(); break; case 2: subt(); break; case 3: multi(); break; case 4: divi(); break; default: main(); } return 0; }