#include <stdio.h>

//?¨????pct%??§?¨????yen????????¨???????¨??????????
int zeikomi(int yen, int pct){
	return yen*(100+pct)/100;
}

//?¨????pct%??§?¨????yen????????????????¨?????????????????????§???
int zeinuki(int yen, int pct){
	if( yen*100%(100+pct) == 0 )
		return yen*100/(100+pct);
	else
		return (yen+1)*100/(100+pct);
}

void main(){
	int x, y, s;
	int ans, tmp;
	int i, j;

	while( scanf("%d%d%d", &x, &y, &s) != EOF ){
		if( x*x+y*y+s*s==0 )	break;

		ans = 0;
		for(i=1; i<=s/2; i++){
			j = zeinuki(s-zeikomi(i,x), x);	//?¨????i,j???????????¢?????????????????????
			if( zeikomi(i,x)+zeikomi(j,x)!=s ) continue;
			tmp = zeikomi(i,y) + zeikomi(j,y);
			if(ans < tmp) ans = tmp;
		}

		printf("%d?\n", ans);
	}
}