#include <math.h>
#include <string.h>
#include <stdio.h>

int min(int a, int b){
	if(a<b){return a;}
	return b;
}
int main(void){
	int A,B,T;
	int ans;
	

	scanf("%d %d %d", &A,&B, &T);
	
	if(T%A == 0 || T%B == 0){
		ans = T;
	}else{
		int x;
		ans = min((T/A + 1) * A, (T/B + 1) * B);
		
		for(x=1;x<(T/A+1);x++){
			int y = ceil((1.0 * T- A * x) / B);
			int tmp = A*x+B*y;
			
			if(ans < tmp){
				break;
			}
			
			if( T <= tmp && tmp <= ans ){
				ans = tmp;
			}
		}
	}
	
	printf("%d\n", ans);
	return 0;
}