#include <stdio.h>
#include <stdlib.h>

long long cutTree(const int* tree, int treeNum, int cuttingHeight);

int main(){
    int N, M;
    scanf("%d %d",&N, &M);
    int* tree = (int*)malloc(sizeof(int)*N);
    int maxHeight = 0;
    for(int i=0; i<N; i++){
        scanf("%d",&tree[i]);
        if(maxHeight<tree[i]) maxHeight = tree[i];
    }

    int start = 0, end = maxHeight;
    int optimalHeight = 0;
    while(start <= end){
        int midHeight = start + (end - start) / 2; // (start + end) / 2 의 오버플로우 방지 형태
        long long cutAmount = cutTree(tree,N,midHeight);
        if(cutAmount<M) end = midHeight - 1;
        else {
            optimalHeight = midHeight;
            start = midHeight + 1;
        }
    }
    
    printf("%d\n",optimalHeight);
    free(tree);
    return 0;
}

long long cutTree(const int* tree, int treeNum, int cuttingHeight) {
    long long totalCut = 0;
    for(int i = 0; i < treeNum; i++){
        if (tree[i] > cuttingHeight) {
            totalCut += tree[i] - cuttingHeight;
        }
    }
    return totalCut;
}