let N = Int(readLine()!)!
let S = String(readLine()!)
let l = (N-3)/2
var c = 0
for i in 0...l{   //文字間隔
    for j in 0...(N-1)-(i+1)*2{
        //print(j,j+(i+1),j+(i+1)*2)
        var t = [S.index(S.startIndex, offsetBy: j)]
        t += [S.index(S.startIndex, offsetBy: j+(i+1))]
        t += [S.index(S.startIndex, offsetBy: j+(i+1)*2)]
        let T = t.map{String(S[$0])}
        if T.joined() == "UMG"{
            c += 1
        }
    }
}
print(c)