#include<bits/stdc++.h>
using namespace std;
int turn(int b,int x){
	int v=1,xb=0;
	while(x!=0){
		if((x%10)>=b)return 2147483647;
		xb+=(x%10)*v;
		v*=b;
		x/=10;
	}
	return xb;
}
int main()
{
int q,p,r;
cin>>q>>p>>r;
for(int i=2;i<=16;++i){
    if(turn(i,q)*turn(i,p)==turn(i,r)){
		printf("%d",i);
		return 0;
	}
}
cout<<0;
return 0;
}