```go
package main
import (
"fmt"
)
func main() {
var n int
fmt.Scan(&n)
var current, maxCapacity int
for i := 0; i < n; i++ {
var a, b int
fmt.Scan(&a, &b)
current -= a
current += b
if current > maxCapacity {
maxCapacity = current
}
}
fmt.Println(maxCapacity)
}
```