foo.c: In function 'main':
foo.c:19:17: error: too few arguments to function 'gcd'
   19 |         int c = gcd(b[0] / a[0]);
      |                 ^~~
foo.c:2:5: note: declared here
    2 | int gcd(int a, int b) {
      |     ^~~
foo.c:12:25: warning: unused variable 'a2' [-Wunused-variable]
   12 |         int b1, a1, b2, a2;
      |                         ^~
foo.c:12:21: warning: unused variable 'b2' [-Wunused-variable]
   12 |         int b1, a1, b2, a2;
      |                     ^~
foo.c:12:17: warning: unused variable 'a1' [-Wunused-variable]
   12 |         int b1, a1, b2, a2;
      |                 ^~
foo.c:12:13: warning: unused variable 'b1' [-Wunused-variable]
   12 |         int b1, a1, b2, a2;
      |             ^~

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