View Compilation Error

0_0_39602389_2815.cpp: In function 'char gc()':
0_0_39602389_2815.cpp:7:34: error: 'frin' was not declared in this scope; did you mean 'fmin'?
    7 |     return p1 == p2 ? p2 = buf + frin(p1 = buf, 1, 1 << 20, stdin),
      |                                  ^~~~
      |                                  fmin