foo.c: In function 'main':
foo.c:9:16: error: too few arguments to function 'fgets'
    9 |         while (fgets(s1) != NULL&& fgets(s2) != NULL) {
      |                ^~~~~
In file included from foo.c:1:
/nix/store/rffag931pvbdiabwwa539wnwg1piqpx0-glibc-2.35-163-dev/include/stdio.h:592:14: note: declared here
  592 | extern char *fgets (char *__restrict __s, int __n, FILE *__restrict __stream)
      |              ^~~~~
foo.c:9:36: error: too few arguments to function 'fgets'
    9 |         while (fgets(s1) != NULL&& fgets(s2) != NULL) {
      |                                    ^~~~~
In file included from foo.c:1:
/nix/store/rffag931pvbdiabwwa539wnwg1piqpx0-glibc-2.35-163-dev/include/stdio.h:592:14: note: declared here
  592 | extern char *fgets (char *__restrict __s, int __n, FILE *__restrict __stream)
      |              ^~~~~
foo.c:8:13: warning: unused variable 's' [-Wunused-variable]
    8 |         int s=0;
      |             ^
foo.c:7:13: warning: unused variable 't' [-Wunused-variable]
    7 |         int t=0;
      |             ^

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