573 - The Snail

#include<stdio.h>

int h,u,d,f;
double move ;
int day;
int main() {

while(scanf("%d %d %d %d", &h, &u, &d, &f)&&h) {
day = 1;
move = 0;
double up = u;
while(1) {

if(up > 0)
move += up;
if(move > h) {
printf("success on day %d\n", day);
break;
}
else if((move - d) < 0) {

printf("failure on day %d\n", day);
break;
}
else {

day++;
move -= d;
up -= u * f / 100.0;
}
}
}
return 0;
}