foo.c: In function 'main':
foo.c:6:2: error: 'cin' undeclared (first use in this function); did you mean 'main'?
  cin>>n>>m;
  ^~~
  main
foo.c:6:2: note: each undeclared identifier is reported only once for each function it appears in
foo.c:11:5: error: too few arguments to function 'printf'
     printf();
     ^~~~~~
In file included from /usr/include/stdio.h:862:0,
                 from foo.c:1:
/usr/include/x86_64-linux-gnu/bits/stdio2.h:102:1: note: declared here
 printf (const char *__restrict __fmt, ...)
 ^~~~~~

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