UVA - 573

#include<stdio.h>
#include<stdlib.h>

int main()
{

    int H,U,D,F;

    while( scanf("%d%d%d%d",&H,&U,&D,&F)  && H != 0) {

        int i = 1;
        float IH  = U,DC = U,p = (U*F)/100.0;
        if(IH > H) goto OUT;
        else {
                IH -= D;
            for(i = 2; ;i++){

                DC -= p;
                if(DC >= 0 && D >= 0)
                    IH += DC;   if(IH > H) break;
                IH -= D;
                if( IH < 0) break;
            }
        }
        OUT:
        if(IH > 0) printf("success on day %d\n",i);
        else       printf("failure on day %d\n",i);
    }
    return 0;
}