#include <bits/stdc++.h> using namespace std; int Change(char *x,int b){ int num = 0; for(int i = 0;i < strlen(x);i++){ if(x[i] - '0' >= b) return -1; num = num * b + x[i] - '0'; } return num; } int main(){ char p[9],q[9],r[9]; scanf("%s %s %s",p,q,r); int B = 0; for(int i = 2;i <= 16;i++){ int pi = Change(p,i); int qi = Change(q,i); int ri = Change(r,i); if(pi == -1 || qi == -1 || ri == -1) continue; if(pi * qi == ri){ B = i; break; } } printf("%d\n",B); return 0; }