Update app.py

app.py

@@ -210,7 +210,7 @@ if st.session_state.screen == 2:
     
     with row5_col3:
         # navigation
-        row4a_col0, row4a_col1, row4a_col2= st.columns([1,1,1], gap="medium")
+        row5a_col0, row5a_col1, row5a_col2= st.columns([1,1,1], gap="medium")
         with row5a_col0:
             if st.button("Back"):
                 if st.session_state.image_counter > 0: