javac Sopra

javac Sopra.java
Sopra.java:10: cannot find symbol
symbol : method metodo1(int)
location: class java.lang.Object
o. metodo1(10); return o;}
^
Sopra.java:10: incompatible types
found : java.lang.Object
required: Sopra
o. metodo1(10); return o;}
^
Sopra.java:22: a has private access in Sopra
{d = a[0]; }
^
Sopra.java:31: c has private access in Sopra
f.c = 10;
^
Sopra.java:32: incompatible types
found : Sopra
required: Sotto
g = f;
^
5 errors