Problem with accentuation in the math environment

Hello I'm using the complexity package to write a text where I would like to highlight some complexity classes.

However the text is being written in a Latin language which requires the use of accents in some words. When I try to make a newfunc using a word as an example, for example, "difícil" the "í" vanished.

\documentclass{article} \usepackage[brazil]{babel} \usepackage[T1]{fontenc} % Support Icelandic Characters \usepackage[utf8]{inputenc} % Support Icelandic Characters \usepackage{type1ec} \usepackage{graphicx} \usepackage{amssymb} \usepackage{booktabs} \usepackage[table, xcdraw, dvipsnames]{xcolor} \usepackage{tkz-graph} \usepackage{subfig} \usepackage{amsmath} \usepackage{float} \captionsetup[figure]{labelfont = {bf}, labelsep = period} \usepackage{array} \newcolumntype{P}[1]{>{\centering\arraybackslash}P{#1}} \usetikzlibrary{arrows} \usetikzlibrary{calc} \usetikzlibrary{positioning} \usepackage[a4paper, portuguese, bookmarks=true, bookmarksnumbered=true, linktocpage, colorlinks, citecolor=black, urlcolor=black, linkcolor=black, filecolor=black, ]{hyperref} \usepackage[square]{natbib} \usepackage{complexity} \newfunc{\dificil}{difícil} \begin{document} problemas $\NP\text{-}\dificil$ \end{document} 

I would like to know how I make the letter "i" appear accented in the math environment.

Thanks