This is the 224th most frequent Hungarian word.
semmi
"Semmi" means "nothing" in English.
Here, 'semmi' negates the existence of 'probléma' (problem), implying there are no problems.
Semmi probléma nincs.
There is no problem.
'Semmi', combined with 'sem', emphasizes the lack of things that interest the person.
Semmi sem érdekli őt.
Nothing interests him/her.
Here, 'semmi' is used to express complete absence, in this case of visibility due to the smoke.