
#include <bits/stdc++.h>
using namespace std;
int main()
{
int weishu=0,shuzi=0,n,t,m;
double e;
cin>>n;
t=n;
if(n<0) n=(-1)*n;
while(n>0)
{
weishu++;
n=n/10;
}
n=t;
if(n<0) n=(-1)*n;
if(weishu>1)
{
while(n>0)
{
m=n%10;
if(m==2) shuzi++;
n=n/10;
}
n=t;
e=shuzi/weishu*100;
if(n<0)
{
e=e*1.5;
if(n%2==0) e=e*2;
}
cout<<setiosflags(ios::fixed)<<setprecision(2)<<e<<"%"<<endl;
}
if(weishu==1)
{
if(n==2) cout<<100.00<<"%"<<endl;
else if(n==-2) cout<<300.00<<"%"<<endl;
else cout<<0.00<<"%"<<endl;
}
return 0;
}
