Grade1 Task69

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

int main()
{
    char num1[10010];
    char num2[10010];
    char tods[10010];for(int i=0;i<10010;i++)tods[i] = '\0';
    char ansp[10010];
    scanf("%s",num1);
    scanf("%s",num2);
    int index1 = strlen(num1) - 1;
    int index2 = strlen(num2) - 1;
    int indexa = 0;
    tods[0] = '0';
    while(index1 >= 0 && index2 >= 0){
        ansp[indexa] = (((num1[index1]-'0') + (num2[index2]-'0') + (tods[indexa] - '0'))%10)+'0';
        tods[indexa+1] =  (((num1[index1]-'0') + (num2[index2]-'0') + (tods[indexa] - '0'))/10) + '0';
        index1--;
        index2--;
        indexa++;
    }
    while(index1 >= 0){
        ansp[indexa] = (((num1[index1]-'0') + (tods[indexa]-'0'))%10) + '0';
        tods[indexa+1] = (((num1[index1--]-'0') + (tods[indexa]-'0'))/10) + '0';
        indexa++;
    }
    while(index2 >= 0){
        ansp[indexa] = (((num2[index2]-'0') + (tods[indexa]-'0'))%10) + '0';
        tods[indexa+1] = (((num2[index2--]-'0') + (tods[indexa]-'0'))/10) + '0';
        indexa++;

    }
    if(tods[indexa] != '\0' && tods[indexa] != '0'){
        ansp[indexa] = tods[indexa];
        indexa++;
    }
    for(int i=indexa-1;i>=0;i--){
        printf("%c",ansp[i]);
    }
    return 0;
}