The lookout tower on Petrin hill is illuminated to show a sign of solidarity and to pay tribute to the generosity and good deeds reacting to the COVID-19 pandemic in Prague, the Czech Republic, May 5, 2020. (Photo by Dana Kesnerova/Xinhua)

The colors of the Czech tricolor national flag are projected on the building of the Cernin palace, the seat of the Foreign Ministry, to show a sign of solidarity and to pay tribute to the generosity and good deeds reacting to the COVID-19 pandemic in Prague, the Czech Republic, May 5, 2020. (Photo by Dana Kesnerova/Xinhua)

The lookout tower on Petrin hill is illuminated to show a sign of solidarity and to pay tribute to the generosity and good deeds reacting to the COVID-19 pandemic in Prague, the Czech Republic, May 5, 2020. (Photo by Dana Kesnerova/Xinhua)

The colors of the Czech tricolor national flag are projected on the building of the National Museum to show a sign of solidarity and to pay tribute to the generosity and good deeds reacting to the COVID-19 pandemic in Prague, the Czech Republic, May 5, 2020. (Photo by Dana Kesnerova/Xinhua)