View Compilation Error

0_0_27220707_25940.cpp: In function 'int main()':
0_0_27220707_25940.cpp:13:3: error: 'len1' was not declared in this scope
   len1=strlen(a)-1;
   ^
0_0_27220707_25940.cpp:13:15: error: 'a' was not declared in this scope
   len1=strlen(a)-1;
               ^
0_0_27220707_25940.cpp:14:3: error: 'len2' was not declared in this scope
   len2=strlen(b)-1;
   ^
0_0_27220707_25940.cpp:14:15: error: 'b' was not declared in this scope
   len2=strlen(b)-1;
               ^
0_0_27220707_25940.cpp:17:26: error: 'c' was not declared in this scope
    if(len1>=0&&len2>=0){ c[i]=a[len1]+b[len2]-'0'+p;}
                          ^
0_0_27220707_25940.cpp:18:25: error: 'c' was not declared in this scope
    if(len1>=0&&len2<0){ c[i]=a[len1]+p;}
                         ^
0_0_27220707_25940.cpp:19:25: error: 'c' was not declared in this scope
    if(len1<0&&len2>=0){ c[i]=b[len2]+p;}
                         ^