#include <stdio.h>

int main(){
    
    int size,ind,x,cnt=0;
    scanf("%d",&size)
    int arr[size];
    for(ind=0;ind<size;ind++){
        scanf("%d",&arr[ind]);
    }
    scanf("%d",&x);
    for(ind=0;ind<size;ind++){
        if(arr[ind] = x){
            arr[ind] = arr[ind+1];
            cnt=1;
        }
    }
    if(cnt != 1){
        printf("Marble not found");
    }
    return 0;
    
}