#include<iostream>
#include<stack>
#include<string.h>
using namespace std;
void multiply(string str,int l){
long long c=0,k=0,i,a;
string str3;
for(i=l-1;i>=0;i--){
a=str[i]-'0';
str3[k++]=((c+(a*2))%10)+'0';
c=(c+(a*2)) /10;
}
if(c){
str3[k]=c+'0';
k=k+1;
}
i=0;
if((str3[i]-'0')>=2)
str3[i]=str3[i]-2;
else{
str3[i]=str3[i]+8;
i++;
while(str3[i]=='0')
{
str3[i]='9';
i++;
}
str3[i]=str3[i]-1;
}
i=k-1;
while (str3[i]=='0') i--;
for(;i>=0;i--)
cout<<str3[i];
cout<<"\n";
}
int main(){
string n;
while(cin>>n){
if(n=="1")
cout<<"1\n";
else
multiply(n,n.length());
}
return 0;
}
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