/in/foo.cc: In member function 'void Bign::out()':
/in/foo.cc:65:24: warning: format '%d' expects argument of type 'int*', but argument 2 has type 'int' [-Wformat=]
       scanf("%d",c[len]);
                        ^
/in/foo.cc:67:21: warning: format '%d' expects argument of type 'int*', but argument 2 has type 'int' [-Wformat=]
    scanf("%04d",c[i]);
                     ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:80:5: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
     for (int i = ans.len - 1; i >= 1; i--)
     ^~~
/in/foo.cc:82:2: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for'
  return 0;
  ^~~~~~