Chicago - Here's a Chicago Public Schools math problem: a system hundreds of millions of dollars in debt, inner-city schools so strapped teachers are digging into their own pockets for supplies, yet on the Gold Coast there's a principal spending thousands to trot around the globe in luxury. Does that add up? Ogden International School Principal Kenneth Staral, who makes $142,000 per year, created an international studies program at the neighborhood school several years ago to teach students about countries, cultures and issues around the world. That program has since expanded to a high school on the Near West Side....