Lucky No, problem

#include <stdio.h>

int main()
{
    int x,y,z,a, digit=7;
    if(digit>10 || digit<100){
        while(x+y==7){
            digit=10*x+y;
        }
    }
    if(digit>100 || digit<1000){
        while(x+y+z==7){
          digit=100*x+10*y+z;
        }
    }
    if(digit>1000){
        while(x+y+z+a==7){
            digit=1000*x+100*y+10*z+a;
        }
    }
    for(;digit<=2014;digit++){
        printf("%d\n", digit);
            }
    return 0;
}