CF #527 A

#include<stdio.h>
int main()
{
    int t;
    scanf("%d",&t);
    while(t--){
        char c[1000];
        int n,k;
        scanf("%d %d",&n,&k);
        int cnt=n/k;
        int mod=n%k;
        int i=0,j;
        c[0]='a';
        while(i<n-mod){
            for(j=0;j<cnt;j++){
                c[i+1]=c[i];
                i++;
            }
            c[i]=c[i]+1;
        }
        char d='a'-1;
        while(i<n){
            c[i]=d+1;
            i++;
            d=d+1;
        }
        for(j=0;j<n;j++)
            printf("%c",c[j]);
        printf("\n");
    }

    return 0;
}