zoj 3203 The Hidden 7's

Given a string of characters, you may find that the word "seven" is hidden inside. For example, in the string "sesveven", five 7's are hidden:

sesveven
sesveven
sesveven
sesveven
sesveven

Your task is to count the number of different 7's.

Note

Upper-case letters are considered as the same as the lower-case letters.

Input

Each case gives the string in a line. The length of the string is not more than 10000.

Output

For each test cases, output in a line the number of different 7's hidden inside the string. The result will be less than 2^63.

Sample Input

sesveven
seSvevEn

Sample Output

5
5

乘法原理


char str[10005];
int main(){
    long long sums,sume,sumv,sumee,sumn;
    while(gets(str)){
       sums=sume=sumv=sumee=sumn=0;
       int len=strlen(str);
       for(int i=0;i<len;i++){
         char ch=tolower(str[i]);
         if(ch=='s')
            sums++;
         else if(ch=='e'){
            sume+=sums;
            sumee+=sumv;
         }
         else if(ch=='v')
            sumv+=sume;

         else if(ch=='n')
            sumn+=sumee;
       }
     cout<<sumn<<endl;
    }

return 0;
}