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


int zjh[1000][2];
int main()
{
    int t,x,m,a,i;
    int hh=0;
    double temp=10000000;

    scanf("%d%d%d",&t,&x,&m);

    
    for(i=0;i<m;i++){
        scanf("%d%d",&zjh[i][0],&zjh[i][1]);
        if((double)(zjh[i][0])/zjh[i][1]<temp) { temp=(double)(zjh[i][0])/zjh[i][1];a=i;}
    }

    if(temp<1||fabs(temp-1)<1e-10) { printf("0\n");return 0;}
    if(temp>t||m==0) printf("%d\n",t*x);
    
    else {

            if(zjh[a][0]%zjh[a][1]==0) {
                hh+=(zjh[a][0]/zjh[a][1]-1)*x;
                t-=zjh[a][0]/zjh[a][1]-1;
                while(t>1){
                    hh+=x;
                    t-=2;
                }
            }
            
            else {
                hh+=(zjh[a][0]/zjh[a][1])*x;
                t-=zjh[a][0]/zjh[a][1];
                while(t>1){
                    hh+=x;
                    t-=2;
                }
            }
            
        }
        
        printf("%d\n",hh);
        
        
        return 0;
    }
    
    
    

    

• Re:Who can tell me why it is wrong answer? Thank you! (12) rencv 2005-10-26 14:59:39
  • Re:Who can tell me why it is wrong answer? Thank you! (13) rencv 2005-10-26 15:01:36
• So me wrong answer? Help! (429) ACM30413 2005-12-29 21:01:44
  • 有BUG! (590) davydc 2005-12-29 22:31:56
    • Re:有BUG! (20) ACM30413 2006-02-06 23:44:30
    • Thank you very much!davydc ! (20) ACM30413 2006-02-06 23:45:16
• 要小心啊! (1260) davydc 2005-12-29 22:24:27
  • Re:要小心啊! (20) Ray_xiang 2006-02-15 19:58:17