#include<stdio.h>                                
#include<math.h>                                
void main()                                
{
    double FD[10][20];        
double a[7][2];                                
int i,j;   

for(i=0;i<7;i++)                                
for(j=0;j<2;j++)                                
scanf("%lf",&a[i][j]);   

for(i=0;i<7;i++)
{
    if(a[i][1]==6)
    {
        FD[0][0]=a[i][0];
        break;
    }
    if(a[i][1]!=6)
    {
        FD[0][0]=0;
    }
}
                                            
printf("%lf \n",FD[0][0]);

}

double FD[10][20]; 假设有FD[0][0],FD[0][1],FD[0][2],FD[0][3],FD[0][4],FD[0][5],FD[0][6],......FD[0][19];
递归计算求值：FD[0][0]+FD[0][1]+FD[0][2]+FD[0][3]+......+FD[0][19];