foo.c: In function ‘main’:
foo.c:6:9: error: ‘cin’ undeclared (first use in this function)
    6 |         cin>>n;
      |         ^~~
foo.c:6:9: note: each undeclared identifier is reported only once for each function it appears in
foo.c:10:21: error: stray ‘\’ in program
   10 |         while(gai>=4\\ping>=3) {
      |                     ^
foo.c:10:22: error: stray ‘\’ in program
   10 |         while(gai>=4\\ping>=3) {
      |                      ^
foo.c:10:21: error: expected ‘)’ before ‘ping’
   10 |         while(gai>=4\\ping>=3) {
      |              ~      ^ ~~~~
      |                     )
foo.c:27:9: error: ‘cout’ undeclared (first use in this function)
   27 |         cout<<drink<<end1;
      |         ^~~~
foo.c:27:22: error: ‘end1’ undeclared (first use in this function)
   27 |         cout<<drink<<end1;
      |                      ^~~~