🐌 A small snail in the well

function main() {    
var depth = parseInt(readLine(), 10);  
  //your code goes here    
var i = 1;    
var day = 7;    
var night = 0;    
if (day > depth ) {        
console.log(i)    
}    else {        
while (day + night < depth ){            
day += 7;            
night -= 2;            
i++;        
}        console.log(i);    
}
}