#include <iostream>

using namespace std;
void cifra(int n, int &x)
{
    x=0;
    while(n)
    {
        if(n%10>x)
            x=n%10;
        n=n/10;
    }

}
int main()
{
    int n=954345, x=0;
    cifra(n,x);
    cout<<x;
}