Main.cc: In function 'int main()':
Main.cc:4:5: error: 'chra' was not declared in this scope
chra a;
^
Main.cc:5:10: error: 'a' was not declared in this scope
cin>>a=b;
^
Main.cc:5:12: error: 'b' was not declared in this scope
cin>>a=b;
^