For

cycle for
#include <stdio.h>
main()
{
    int m=0,d=0,k=0,pr=1,sum=0,sk=0,i;
    float y;
    printf("Vvedite M: ");
    scanf("%d",&m);
    printf("Vvedite D: ");
    scanf("%d",&d);
    printf("Vvedite K: ");
    scanf("%d",&k);

    for (i=1;i<=3;i++)
    {
        sk=d+i;
        pr*=sk;
    }

    sk=0;
    sum=0;
    for (i=1;i<=4;i++)
    {
        sk=i+5;
        sum+=sk;
    }

    k*=k;
    y=m*(k*pr+1./sum);
    printf("Y=%f",y);
}