answer.code:1:9: error: ‘xr’ does not name a type
    1 |         xr=(xr<<3)+(xr<<1)+(cr^48),cr=getchar();
      |         ^~
answer.code:2:5: error: expected unqualified-id before ‘return’
    2 |     return xr*F;
      |     ^~~~~~
answer.code:3:1: error: expected declaration before ‘}’ token
    3 | }
      | ^
answer.code: In function ‘int main()’:
answer.code:9:7: error: ‘read’ was not declared in this scope
    9 |     n=read(),m=read(),p=read();
      |       ^~~~
answer.code:17:21: error: ‘swap’ was not declared in this scope
   17 |             if(x>y) swap(x,y);
      |                     ^~~~
answer.code:18:26: error: ‘min’ was not declared in this scope; did you mean ‘main’?
   18 |             f[i][j]+=0.5*min(x,y);
      |                          ^~~
      |                          main
answer.code:24:5: error: ‘printf’ was not declared in this scope
   24 |     printf("%.9lf\n",f[n][m]);
      |     ^~~~~~
answer.code:1:1: note: ‘printf’ is defined in header ‘<cstdio>’; did you forget to ‘#include <cstdio>’?
  +++ |+#include <cstdio>
    1 |         xr=(xr<<3)+(xr<<1)+(cr^48),cr=getchar();