main = 1+1
Standard input is empty
[1 of 1] Compiling Main ( prog.hs, prog.o )
prog.hs:1:7:
No instance for (Num (IO a))
arising from the literal `1' at prog.hs:1:7
Possible fix: add an instance declaration for (Num (IO a))
In the first argument of `(+)', namely `1'
In the expression: 1 + 1
In the definition of `main': main = 1 + 1
Standard output is empty