#include <stdio.h>

int main() {
    int up,down,height;
    int cnt=0;
    scanf("%d%d%d",&up,&down,&height);
    //cnt-1 *(up-down)+up>=height
    //(A + B - 1) / B 올림!
    cnt=(height-up + (up-down-1) )/(up-down)  +1;
    printf("%d",cnt);
    return 0;
}
10 2 5