What is the logical operator for but? I saw a sentence like,
I am fine but he has flu.

Now I have to convert it into logical sentence using logical operators. I do not have any idea what should but be translated to. Please help me out. 
Thanks

This seems like an exercise in semantics. I cannot think of a logical operator which fits other than $\land$.
However, if we define the predicate $\operatorname{Fine}(x)$ which holds if and only if $x$ is fine, then we can assume "has the flu" is $\lnot\operatorname{Fine}(x)$.
In which case we can write the sentence:
$$\operatorname{Fine}(\textbf{me})\land\lnot\operatorname{Fine}(\textbf{him})$$
If you want to distinguish $\operatorname{Flu}(x)$ from simply $\lnot\operatorname{Fine}(x)$, then we are reduced to:
$$\operatorname{Fine}(\textbf{me})\land\operatorname{Flu}(\textbf{him})$$
