let inpt = readLine()!.split(separator: " ").map({Int($0)});
let boxCount = inpt[0]!;
let removeCount = inpt[1]!;

var candyList = readLine()!.split(separator: " ").map({Int($0)!}).sorted(by: {$0<$1});
var ans=0;
for _ in 1...removeCount {
    candyList[0] = candyList[0]-1;
    if(candyList[0]<=0) {
        candyList.removeFirst();
        ans+=1;
    }
}

print(ans);