foo.cc: In function 'int main()':
foo.cc:20:17: warning: conversion lacks type at end of format [-Wformat=]
   20 |         scanf("%*");
      |                 ^
foo.cc:20:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   20 |         scanf("%*");
      |         ~~~~~^~~~~~
foo.cc:21:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   21 |         scanf("%s",ch);
      |         ~~~~~^~~~~~~~~

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