foo.c: In function 'year':
foo.c:4:27: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
    4 |         if ((year % 4==0) && (year % 100!=0)|| year % 400 ==0)
      |             ~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~
foo.c: In function 'main':
foo.c:57:9: warning: implicit declaration of function 'scanf_s'; did you mean 'scanf'? [-Wimplicit-function-declaration]
   57 |         scanf_s("%d %d %d", &year1, &month1, &day1);
      |         ^~~~~~~
      |         scanf
/nix/store/j2gmfdd29cp3rcvghmn1a5kgcnmf8myp-binutils-2.40/bin/ld: /tmp/ccZmHXAv.o: in function `main':
foo.c:(.text.startup+0x1c): undefined reference to `scanf_s'
/nix/store/j2gmfdd29cp3rcvghmn1a5kgcnmf8myp-binutils-2.40/bin/ld: foo.c:(.text.startup+0x37): undefined reference to `scanf_s'
collect2: error: ld returned 1 exit status

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