let x = readLine()
let w = readLine()!
var l = 0
var v = 0
var isV = false

for n in w.characters {
    if n == "U" {
        l += 1
    } else {
        l -= 1
    }
    if l < 0 && !isV {
        isV = true
        v += 1
    } else if l == 0 {
        isV = false
    }    
}
print(v)