#include<bits/stdc++.h> using namespace std; int z(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]; cin >> p >> q >> r; int B = 0; for(int i = 2; i <= 16;i++) { int pi = z(p,i); int qi = z(q,i); int ri = z(r,i); if(pi == -1 || qi == -1 || ri == -1) continue; if(pi * qi == ri) { B = i; break; } } cout << B; }