answer.code: In function ‘int cd()’:
answer.code:116:15: error: lvalue required as left operand of assignment
  116 |     else if(c1-d1=1)
      |             ~~^~~
answer.code:141:15: error: lvalue required as left operand of assignment
  141 |     else if(d1-c1=1)
      |             ~~^~~
answer.code: In function ‘void ds()’:
answer.code:29:14: warning: ignoring return value of ‘int scanf(const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
   29 |         scanf("%d%d",&x,&y);
      |         ~~~~~^~~~~~~~~~~~~~
answer.code:31:14: warning: ignoring return value of ‘int scanf(const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
   31 |         scanf("%s",s);
      |         ~~~~~^~~~~~~~
answer.code: In function ‘int cd()’:
answer.code:167:1: warning: control reaches end of non-void function [-Wreturn-type]
  167 | }
      | ^