foo.c:1:1: error: unknown type name 'nt'; did you mean 'int'?
    1 | nt main()
      | ^~
      | int
foo.c: In function 'main':
foo.c:11:5: warning: implicit declaration of function 'scanf' [-Wimplicit-function-declaration]
   11 |     scanf("%d",&a);
      |     ^~~~~
foo.c:1:1: note: include '<stdio.h>' or provide a declaration of 'scanf'
  +++ |+#include <stdio.h>
    1 | nt main()
foo.c:11:5: warning: incompatible implicit declaration of built-in function 'scanf' [-Wbuiltin-declaration-mismatch]
   11 |     scanf("%d",&a);
      |     ^~~~~
foo.c:11:5: note: include '<stdio.h>' or provide a declaration of 'scanf'
foo.c:13:9: warning: implicit declaration of function 'printf' [-Wimplicit-function-declaration]
   13 |         printf("2+2=4");
      |         ^~~~~~
foo.c:13:9: note: include '<stdio.h>' or provide a declaration of 'printf'
foo.c:13:9: warning: incompatible implicit declaration of built-in function 'printf' [-Wbuiltin-declaration-mismatch]
foo.c:13:9: note: include '<stdio.h>' or provide a declaration of 'printf'
foo.c:40:25: warning: incompatible implicit declaration of built-in function 'printf' [-Wbuiltin-declaration-mismatch]
   40 |                         printf("%d+%d=%d\n",b,c,a);
      |                         ^~~~~~
foo.c:40:25: note: include '<stdio.h>' or provide a declaration of 'printf'

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