#include<string>
#include<cmath>

typedef long long ll;

using namespace std; 

const int N=1e6+10;

int f (int x,int y)//x是传进去的值，y是进制数
{
	ll a[N];
	ll k=0;
	ll sum=0,ans;
	while (x)
	{
		a[k++]=x%y;
		x/=y;	
	}
	for (int i=0 ; i<k ;i++)
	{
		ans = pow(y,i);
		sum += ans;
	}
	return sum;
} 

int main()
{
	ll p,q,r,flag=0;
	ll x,y,z;
	cin >> p >> q >>r;
	for (int i=2 ; i<=16; i++)
	{
		x = f(p,i), y=f(q,i), z=f(r,i);
		if (x+y==z)
		{
			cout << i;
			flag=1;
			break;
		}
	}
	if (flag==0) cout<<0;
	return 0;	
}