Visitors pose for a picture in front of graffiti art created by Brazilian artist Vermelho during the 3rd annual Graffiti Fine Art Biennial International exhibit, at the Pavilion of Brazilian Cultures, in Sao Paulo, Brazil, Tuesday, April 21, 2015. The month-long event features the work of more than 60 street artists, representing 11 countries. (Photo by Andre Penner/AP Photo)

Graffiti installation created by Brazilian artist Mundano that speaks to the severe drought is displayed during the 3rd annual Graffiti Fine Art Biennial International exhibit, at the Pavilion of Brazilian Cultures, in Sao Paulo, Brazil, Tuesday, April 21, 2015. (Photo by Andre Penner/AP Photo)

A family pose next to a work by Brazilian artist Tars during the 3th International Biennial Fine Art Graffiti exhibition at the Ibirapuera park in Sao Paulo April 21, 2015. (Photo by Nacho Doce/Reuters)

A girl looks at a work by Brazilian artist Sipros during the 3th International Biennial Fine Art Graffiti exhibition at the Ibirapuera park in Sao Paulo April 21, 2015. (Photo by Nacho Doce/Reuters)

Women dance in front of a work by Brazilian artist Sipros during the 3th International Biennial Fine Art Graffiti exhibition at the Ibirapuera park in Sao Paulo April 21, 2015. (Photo by Nacho Doce/Reuters)

A woman poses next to a work by Brazilian artist Nilo Zack during the 3th International Biennial Fine Art Graffiti exhibition at the Ibirapuera park in Sao Paulo April 21, 2015. (Photo by Nacho Doce/Reuters)

Graffiti art created by Brazilian artist Waleska is displayed during the 3rd annual Graffiti Fine Art Biennial International exhibit, at the Pavilion of Brazilian Cultures, in Sao Paulo, Brazil, Tuesday, April 21, 2015. (Photo by Andre Penner/AP Photo)

Visitors look at graffiti art created by Brazilian artist Image during the 3rd annual Graffiti Fine Art Biennial International exhibit, at the Pavilion of Brazilian Cultures, in Sao Paulo, Brazil, Tuesday, April 21, 2015. (Photo by Andre Penner/AP Photo)