Solution of URI 2016 :: D as in Daedalus

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/**Bismillahir Rahmanir Rahim.**/

#include <stdio.h>
int main()
{
    int p, r, q;
    scanf("%d%d", &p, &r);
    q = p-1;
    int ara[q], bnk, b, cnt=0, sum=0, i, j, nit;
    for(i=1; i<=r; i++)
    {
        sum = 0;
        scanf("%d", &bnk);
        scanf("%d", &b);
        for(j=0; j<q; j++)
        {
            scanf("%d", &ara[j]);
            sum += ara[j];
        }
        if(sum>=bnk)
            continue;
        if(sum+b > bnk) b=0;
        nit = bnk - sum;
        if(bnk-sum>=10000) cnt += (10000 - b);
        else if((bnk-sum)>=1000) cnt += (1000 - b);
        else if((bnk-sum)>=100) cnt += (100 - b);
        else if((bnk-sum)>=10) cnt += (10 - b);
        else if((bnk-sum)>=1) cnt += (1- b);
    }
    printf("%d\n", cnt);
    return 0;
}