wa in abcstr

#include<string.h>
#include <stdio.h>

int main()
{
   long long int m,n,s=0,a=0,b=0,c=0,i,j,k;
    char arr[1000000],ch;
    scanf("%s",arr);
    m=strlen(arr);
    if((m%3)==0)
        n=m;
    else if(((m-1)%3)==0)
    n=m-1;
    else
    n=m-2;

    for(i=3;i<=n;i=i+3)
    {

        for(j=0;j<=m-i;j++)
        {
            k=i;
           while(k!=0)
           {
            ch=arr[(j+k-1)];
            if(ch=='a')
            a++;
            else if(ch=='b')
            b++;
            else 
            c++;
            k--;
           }

            if((a==b)&&(b==c)&&(c==a))
            s++;
            a=0;
            b=0;
            c=0;
        }


    }
    printf("%lld",s);
    return 0;
}