#include<bits/stdc++.h>
using namespace std;
using Int = long long;
template<typename T1,typename T2> inline void chmin(T1 &a,T2 b){if(a>b) a=b;}
template<typename T1,typename T2> inline void chmax(T1 &a,T2 b){if(a<b) a=b;}

//INSERT ABOVE HERE
signed main(){
  Int a,b,t;
  cin>>a>>b>>t;
  if(a>=t){
    cout<<a<<endl;
    return 0;
  }
  const Int INF = 1e15;
  if(b>=100){
    Int ans=INF;
    for(Int i=0;i-b<=t;i+=b){
      if(i>=t) chmin(ans,i);
      else chmin(ans,i+(t-i+a-1)/a*a);
    }
    cout<<ans<<endl;
    return 0;
  }
  const Int MAX = 1e7 + 1000;
  if(t<=1e7){
    vector<signed> dp(MAX,0);
    dp[0]=1;
    for(Int i=0;i+b<MAX;i++)
      dp[i+a]|=dp[i],dp[i+b]|=dp[i];
    for(Int i=t;i<MAX;i++){
      if(dp[i]){
        cout<<i<<endl;
        break;
      }
    }
    return 0;
  }  
  Int g=__gcd(a,b);
  cout<<(t+g-1)/g*g<<endl;
  return 0;
}